PHP 7.2 버전용으로 올림!

vendor/symfony/lock/composer.json

@@ -16,8 +16,7 @@
         }
     ],
     "require": {
-        "php": "^5.5.9|>=7.0.8",
-        "symfony/polyfill-php70": "~1.0",
+        "php": "^7.1.3",
         "psr/log": "~1.0"
     },
     "require-dev": {
@@ -32,7 +31,7 @@
     "minimum-stability": "dev",
     "extra": {
         "branch-alias": {
-            "dev-master": "3.4-dev"
+            "dev-master": "4.1-dev"
         }
     }
 }