Preliminary implementation of master API keys

Part of #205

src/Api/ApiKey.php

@@ -0,0 +1,57 @@
+<?php
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Flarum\Api;
+
+use Flarum\Core\Model;
+use DateTime;
+
+/**
+ * @todo document database columns with @property
+ */
+class ApiKey extends Model
+{
+    /**
+     * {@inheritdoc}
+     */
+    protected $table = 'api_keys';
+
+    /**
+     * Use a custom primary key for this model.
+     *
+     * @var bool
+     */
+    public $incrementing = false;
+
+    /**
+     * Generate an API key.
+     *
+     * @return static
+     */
+    public static function generate()
+    {
+        $key = new static;
+
+        $key->id = str_random(40);
+
+        return $key;
+    }
+
+    /**
+     * Get the given key only if it is valid.
+     *
+     * @param string $key
+     * @return static|null
+     */
+    public static function valid($key)
+    {
+        return static::where('id', $key)->first();
+    }
+}