Fix symfony version

Author: alibo

composer.json

@@ -12,7 +12,7 @@
     "require": {
         "php": ">=5.5.9",
         "react/dns": "~0.4.0",
-        "symfony/console": "^3.0"
+        "symfony/console": "~2.8|~3.0"
     },
     "autoload": {
         "psr-4": {