Update symfony to ^4.0

Author: antonmedv

composer.json

@@ -17,7 +17,7 @@
     {
       "name": "Anton Medvedev",
       "email": "anton@medv.io",
-      "homepage": "http://medv.io"
+      "homepage": "https://medv.io"
     }
   ],
   "autoload": {
@@ -29,10 +29,10 @@
   },
   "require": {
     "php": ">=5.3.3",
-    "symfony/console": "^2.1|^3.0"
+    "symfony/console": "~2.7|~3.0|~4.0"
   },
   "require-dev": {
-    "symfony/process": "~2.1",
+    "symfony/process": "~2.7|~3.0|~4.0",
     "mikey179/vfsStream": "1.1.0",
     "phpunit/phpunit": "3.7.*"
   }