Support Laravel v5.7+ and drop v5.6

Author: Omranic

composer.json

@@ -39,13 +39,13 @@
     ],
     "require": {
         "php": "^7.1.3",
-        "illuminate/auth": "~5.6.0",
-        "illuminate/bus": "~5.6.0",
-        "illuminate/contracts": "~5.6.0",
-        "illuminate/http": "~5.6.0",
-        "illuminate/routing": "~5.6.0",
-        "illuminate/support": "~5.6.0",
-        "illuminate/validation": "~5.6.0",
+        "illuminate/auth": "~5.7.0",
+        "illuminate/bus": "~5.7.0",
+        "illuminate/contracts": "~5.7.0",
+        "illuminate/http": "~5.7.0",
+        "illuminate/routing": "~5.7.0",
+        "illuminate/support": "~5.7.0",
+        "illuminate/validation": "~5.7.0",
         "spatie/laravel-schemaless-attributes": "~1.1.0",
         "watson/validating": "^3.1.0"
     },