FEATURE: add Request class for handling user registration

Laravel provides functionality for validating and authorization of incoming form requests. This commit adds this functionality to user registration.

app/Http/Requests/CreateNewUser.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace App\Http\Requests;
+
+use App\Http\Requests\Request;
+use App\Models\User;
+
+class CreateNewUser extends Request
+{
+    /**
+     * Determine if the user is authorized to make this request.
+     *
+     * @return bool
+     */
+    public function authorize()
+    {
+        return \Auth::$user->role == User::ROLE_ADMIN;
+    }
+
+    /**
+     * Get the validation rules that apply to the request.
+     *
+     * @return array
+     */
+    public function rules()
+    {
+        return [
+            'role'     => 'required',
+            'email'    => 'required|email|max:128|unique:users',
+            'password' => 'required|min:6'
+        ];
+    }
+}