Update framework dependency for laravel 6.x

Author: Ubuntu

composer.json

@@ -12,11 +12,9 @@
         }
     ],
     "require": {
-        "laravel/framework": "~5.5"
+        "laravel/framework": "^5.5|^6.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "~4.0",
-        "squizlabs/php_codesniffer": "^3.2"
     },
     "autoload": {
         "psr-4": {