Removes PHP 5 version constraint as we're using PHP 7 features (#31)

Author: moebrowne

composer.json

@@ -17,7 +17,7 @@
         }
     ],
     "require": {
-        "php" : "^5.5|^7.0",
+        "php" : "^7.0",
         "illuminate/support": "^5.3",
         "illuminate/http": "^5.3",
         "symfony/dom-crawler": "^2.7|^3.0|^4.0",