diff --git a/.travis.yml b/.travis.yml
index 1c5bcae..9de21d7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,14 +2,21 @@ language: php
 
 php:
     - 7.0
+    - 7.1
     - nightly
 
 env:
-    matrix:
-        - COMPOSERFLAGS="--prefer-stable"
-        - COMPOSERFLAGS="--prefer-lowest"
+    - COMPOSERFLAGS=
+    - COMPOSERFLAGS=--prefer-lowest
 
 matrix:
+    exclude:
+        - php: 7.0
+          env: COMPOSERFLAGS=
+        - php: 7.1
+          env: COMPOSERFLAGS=--prefer-lowest
+        - php: nightly
+          env: COMPOSERFLAGS=--prefer-lowest
     allow_failures:
         - php: nightly
 
diff --git a/bin/dcv b/bin/dcv
old mode 100644
new mode 100755
diff --git a/composer.json b/composer.json
index fed01ce..1b6589f 100644
--- a/composer.json
+++ b/composer.json
@@ -2,7 +2,7 @@
     "name": "pmsipilot/docker-compose-viz",
     "description": "Docker compose graph visualization",
     "require": {
-        "symfony/yaml": "^3.1",
+        "symfony/yaml": "^3.1 || ^4@dev",
         "symfony/console": "^3.1",
         "clue/graph": "^0.9",
         "graphp/graphviz": "^0.2"
diff --git a/composer.lock b/composer.lock
index 70160e5..a6bbcb3 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,8 +4,8 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
-    "hash": "696a6b3b1a107635fb32ba218a89999b",
-    "content-hash": "507a2cc5a9d6155e47cca472793790e0",
+    "hash": "0d62100317a058684fbda02b5b1a8b28",
+    "content-hash": "2a9cfe4bb29738f0495cc645b6ed6c65",
     "packages": [
         {
             "name": "clue/graph",
@@ -193,16 +193,16 @@
         },
         {
             "name": "symfony/console",
-            "version": "v3.2.1",
+            "version": "v3.3.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/console.git",
-                "reference": "d12aa9ca20f4db83ec58410978dab6afcb9d6aaa"
+                "reference": "c80e63f3f5e3a331bfc25e6e9332b10422eb9b05"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/console/zipball/d12aa9ca20f4db83ec58410978dab6afcb9d6aaa",
-                "reference": "d12aa9ca20f4db83ec58410978dab6afcb9d6aaa",
+                "url": "https://api.github.com/repos/symfony/console/zipball/c80e63f3f5e3a331bfc25e6e9332b10422eb9b05",
+                "reference": "c80e63f3f5e3a331bfc25e6e9332b10422eb9b05",
                 "shasum": ""
             },
             "require": {
@@ -210,10 +210,15 @@
                 "symfony/debug": "~2.8|~3.0",
                 "symfony/polyfill-mbstring": "~1.0"
             },
+            "conflict": {
+                "symfony/dependency-injection": "<3.3"
+            },
             "require-dev": {
                 "psr/log": "~1.0",
+                "symfony/dependency-injection": "~3.3",
                 "symfony/event-dispatcher": "~2.8|~3.0",
                 "symfony/filesystem": "~2.8|~3.0",
+                "symfony/http-kernel": "~2.8|~3.0",
                 "symfony/process": "~2.8|~3.0"
             },
             "suggest": {
@@ -225,7 +230,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "3.2-dev"
+                    "dev-master": "3.3-dev"
                 }
             },
             "autoload": {
@@ -252,20 +257,20 @@
             ],
             "description": "Symfony Console Component",
             "homepage": "https://symfony.com",
-            "time": "2016-12-11 14:34:22"
+            "time": "2017-05-28 14:08:56"
         },
         {
             "name": "symfony/debug",
-            "version": "v3.2.1",
+            "version": "v3.3.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/debug.git",
-                "reference": "9f923e68d524a3095c5a2ae5fc7220c7cbc12231"
+                "reference": "ef5f19a7a68075a0bd05969a329ead3b0776fb7a"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/debug/zipball/9f923e68d524a3095c5a2ae5fc7220c7cbc12231",
-                "reference": "9f923e68d524a3095c5a2ae5fc7220c7cbc12231",
+                "url": "https://api.github.com/repos/symfony/debug/zipball/ef5f19a7a68075a0bd05969a329ead3b0776fb7a",
+                "reference": "ef5f19a7a68075a0bd05969a329ead3b0776fb7a",
                 "shasum": ""
             },
             "require": {
@@ -276,13 +281,12 @@
                 "symfony/http-kernel": ">=2.3,<2.3.24|~2.4.0|>=2.5,<2.5.9|>=2.6,<2.6.2"
             },
             "require-dev": {
-                "symfony/class-loader": "~2.8|~3.0",
                 "symfony/http-kernel": "~2.8|~3.0"
             },
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "3.2-dev"
+                    "dev-master": "3.3-dev"
                 }
             },
             "autoload": {
@@ -309,7 +313,7 @@
             ],
             "description": "Symfony Debug Component",
             "homepage": "https://symfony.com",
-            "time": "2016-11-16 22:18:16"
+            "time": "2017-05-27 16:02:27"
         },
         {
             "name": "symfony/polyfill-mbstring",
@@ -372,23 +376,23 @@
         },
         {
             "name": "symfony/yaml",
-            "version": "v3.2.1",
+            "version": "dev-master",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/yaml.git",
-                "reference": "a7095af4b97a0955f85c8989106c249fa649011f"
+                "reference": "5037d791db10d60b23385b64374ee9f29b945945"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/yaml/zipball/a7095af4b97a0955f85c8989106c249fa649011f",
-                "reference": "a7095af4b97a0955f85c8989106c249fa649011f",
+                "url": "https://api.github.com/repos/symfony/yaml/zipball/5037d791db10d60b23385b64374ee9f29b945945",
+                "reference": "5037d791db10d60b23385b64374ee9f29b945945",
                 "shasum": ""
             },
             "require": {
-                "php": ">=5.5.9"
+                "php": "^7.1.3"
             },
             "require-dev": {
-                "symfony/console": "~2.8|~3.0"
+                "symfony/console": "~3.4|~4.0"
             },
             "suggest": {
                 "symfony/console": "For validating YAML files using the lint command"
@@ -396,7 +400,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "3.2-dev"
+                    "dev-master": "4.0-dev"
                 }
             },
             "autoload": {
@@ -423,7 +427,7 @@
             ],
             "description": "Symfony Yaml Component",
             "homepage": "https://symfony.com",
-            "time": "2016-12-10 10:07:06"
+            "time": "2017-05-28 11:01:50"
         }
     ],
     "packages-dev": [
@@ -539,23 +543,23 @@
         },
         {
             "name": "sebastian/diff",
-            "version": "1.4.1",
+            "version": "1.4.3",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/diff.git",
-                "reference": "13edfd8706462032c2f52b4b862974dd46b71c9e"
+                "reference": "7f066a26a962dbe58ddea9f72a4e82874a3975a4"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sebastianbergmann/diff/zipball/13edfd8706462032c2f52b4b862974dd46b71c9e",
-                "reference": "13edfd8706462032c2f52b4b862974dd46b71c9e",
+                "url": "https://api.github.com/repos/sebastianbergmann/diff/zipball/7f066a26a962dbe58ddea9f72a4e82874a3975a4",
+                "reference": "7f066a26a962dbe58ddea9f72a4e82874a3975a4",
                 "shasum": ""
             },
             "require": {
-                "php": ">=5.3.3"
+                "php": "^5.3.3 || ^7.0"
             },
             "require-dev": {
-                "phpunit/phpunit": "~4.8"
+                "phpunit/phpunit": "^4.8.35 || ^5.7 || ^6.0"
             },
             "type": "library",
             "extra": {
@@ -587,29 +591,32 @@
             "keywords": [
                 "diff"
             ],
-            "time": "2015-12-08 07:14:41"
+            "time": "2017-05-22 07:24:03"
         },
         {
             "name": "symfony/event-dispatcher",
-            "version": "v3.2.1",
+            "version": "v3.3.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/event-dispatcher.git",
-                "reference": "e8f47a327c2f0fd5aa04fa60af2b693006ed7283"
+                "reference": "a9f8b02b0ef07302eca92cd4bba73200b7980e9c"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/event-dispatcher/zipball/e8f47a327c2f0fd5aa04fa60af2b693006ed7283",
-                "reference": "e8f47a327c2f0fd5aa04fa60af2b693006ed7283",
+                "url": "https://api.github.com/repos/symfony/event-dispatcher/zipball/a9f8b02b0ef07302eca92cd4bba73200b7980e9c",
+                "reference": "a9f8b02b0ef07302eca92cd4bba73200b7980e9c",
                 "shasum": ""
             },
             "require": {
                 "php": ">=5.5.9"
             },
+            "conflict": {
+                "symfony/dependency-injection": "<3.3"
+            },
             "require-dev": {
                 "psr/log": "~1.0",
                 "symfony/config": "~2.8|~3.0",
-                "symfony/dependency-injection": "~2.8|~3.0",
+                "symfony/dependency-injection": "~3.3",
                 "symfony/expression-language": "~2.8|~3.0",
                 "symfony/stopwatch": "~2.8|~3.0"
             },
@@ -620,7 +627,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "3.2-dev"
+                    "dev-master": "3.3-dev"
                 }
             },
             "autoload": {
@@ -647,20 +654,20 @@
             ],
             "description": "Symfony EventDispatcher Component",
             "homepage": "https://symfony.com",
-            "time": "2016-10-13 06:29:04"
+            "time": "2017-05-04 12:23:07"
         },
         {
             "name": "symfony/filesystem",
-            "version": "v3.2.1",
+            "version": "v3.3.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/filesystem.git",
-                "reference": "8d4cf7561a5b17e5eb7a02b80d0b8f014a3796d4"
+                "reference": "c709670bf64721202ddbe4162846f250735842c0"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/filesystem/zipball/8d4cf7561a5b17e5eb7a02b80d0b8f014a3796d4",
-                "reference": "8d4cf7561a5b17e5eb7a02b80d0b8f014a3796d4",
+                "url": "https://api.github.com/repos/symfony/filesystem/zipball/c709670bf64721202ddbe4162846f250735842c0",
+                "reference": "c709670bf64721202ddbe4162846f250735842c0",
                 "shasum": ""
             },
             "require": {
@@ -669,7 +676,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "3.2-dev"
+                    "dev-master": "3.3-dev"
                 }
             },
             "autoload": {
@@ -696,20 +703,20 @@
             ],
             "description": "Symfony Filesystem Component",
             "homepage": "https://symfony.com",
-            "time": "2016-11-24 00:46:43"
+            "time": "2017-05-28 14:08:56"
         },
         {
             "name": "symfony/finder",
-            "version": "v3.2.1",
+            "version": "v3.3.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/finder.git",
-                "reference": "a69cb5d455b4885ca376dc5bb3e1155cc8c08c4b"
+                "reference": "30cb2a2c09627823a7243638dd456de4e2748fed"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/finder/zipball/a69cb5d455b4885ca376dc5bb3e1155cc8c08c4b",
-                "reference": "a69cb5d455b4885ca376dc5bb3e1155cc8c08c4b",
+                "url": "https://api.github.com/repos/symfony/finder/zipball/30cb2a2c09627823a7243638dd456de4e2748fed",
+                "reference": "30cb2a2c09627823a7243638dd456de4e2748fed",
                 "shasum": ""
             },
             "require": {
@@ -718,7 +725,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "3.2-dev"
+                    "dev-master": "3.3-dev"
                 }
             },
             "autoload": {
@@ -745,20 +752,20 @@
             ],
             "description": "Symfony Finder Component",
             "homepage": "https://symfony.com",
-            "time": "2016-12-13 09:39:43"
+            "time": "2017-05-25 23:10:31"
         },
         {
             "name": "symfony/process",
-            "version": "v3.2.1",
+            "version": "v3.3.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/process.git",
-                "reference": "02ea84847aad71be7e32056408bb19f3a616cdd3"
+                "reference": "8e30690c67aafb6c7992d6d8eb0d707807dd3eaf"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/process/zipball/02ea84847aad71be7e32056408bb19f3a616cdd3",
-                "reference": "02ea84847aad71be7e32056408bb19f3a616cdd3",
+                "url": "https://api.github.com/repos/symfony/process/zipball/8e30690c67aafb6c7992d6d8eb0d707807dd3eaf",
+                "reference": "8e30690c67aafb6c7992d6d8eb0d707807dd3eaf",
                 "shasum": ""
             },
             "require": {
@@ -767,7 +774,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "3.2-dev"
+                    "dev-master": "3.3-dev"
                 }
             },
             "autoload": {
@@ -794,20 +801,20 @@
             ],
             "description": "Symfony Process Component",
             "homepage": "https://symfony.com",
-            "time": "2016-11-24 10:40:28"
+            "time": "2017-05-22 12:32:03"
         },
         {
             "name": "symfony/stopwatch",
-            "version": "v3.2.1",
+            "version": "v3.3.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/stopwatch.git",
-                "reference": "5b139e1c4290e6c7640ba80d9c9b5e49ef22b841"
+                "reference": "602a15299dc01556013b07167d4f5d3a60e90d15"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/stopwatch/zipball/5b139e1c4290e6c7640ba80d9c9b5e49ef22b841",
-                "reference": "5b139e1c4290e6c7640ba80d9c9b5e49ef22b841",
+                "url": "https://api.github.com/repos/symfony/stopwatch/zipball/602a15299dc01556013b07167d4f5d3a60e90d15",
+                "reference": "602a15299dc01556013b07167d4f5d3a60e90d15",
                 "shasum": ""
             },
             "require": {
@@ -816,7 +823,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "3.2-dev"
+                    "dev-master": "3.3-dev"
                 }
             },
             "autoload": {
@@ -843,12 +850,14 @@
             ],
             "description": "Symfony Stopwatch Component",
             "homepage": "https://symfony.com",
-            "time": "2016-06-29 05:43:10"
+            "time": "2017-04-12 14:14:56"
         }
     ],
     "aliases": [],
     "minimum-stability": "stable",
-    "stability-flags": [],
+    "stability-flags": {
+        "symfony/yaml": 20
+    },
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": [],