Ensure access_token are removed

When we remove the client, we should ensure that access_token are also removed.

To ensure that, I created a test that generated an access_token. So when we remove the client, this association should be cascaded and shouldn’t generate an error.

Also I moved some Api related stuff to the ApiBundle (like the developer controler and ClientType form)

src/Wallabag/ApiBundle/Entity/Client.php

@@ -30,6 +30,11 @@ class Client extends BaseClient
      */
     protected $refreshTokens;
 
+    /**
+     * @ORM\OneToMany(targetEntity="AccessToken", mappedBy="client", cascade={"remove"})
+     */
+    protected $accessTokens;
+
     public function __construct()
     {
         parent::__construct();