Added option for user_claims to be in a object & fixes

[itbm]

I have added the option for user_claims to we wrapped in an object if they are not required at the token root level.

"user": {
    "name": "User Name",
    "email": "[email protected]"
  },

[itbm]

Have added in fix for oauth permissions check due to failing build, this now matches PassportServiceProvider (see also #3)

[itbm]

Changed url() to env('APP_URL'), as the default url() blocks dump-autoload:

In UrlGenerator.php line 102:

  Type error: Argument 2 passed to Illuminate\Routing\UrlGenerator::__construct() must be an instance of Illuminate\Http\Request, null given, called in...