Change minimum required php version

Author: Reza Shadman

composer.json

@@ -10,7 +10,7 @@
         }
     ],
     "require": {
-        "php": "^7.1",
+        "php": "^7.0",
         "illuminate/database": "~5.5.0|~5.6.0",
         "illuminate/support": "~5.5.0|~5.6.0"
     },