Shifting to that NoSQL life

Dropped the database abstraction layer, added a rudimentary MongoDB class,
dopped all of the interface classes for the OAuth2 library and updated the
dependencies to use @bshaffer's OAuth2 class as it has MongoDB support out of
the box.

src/OAuth2/ScopeStorage.php

@@ -1,26 +0,0 @@
-<?php
-
-namespace Pickles\OAuth2;
-
-use \League\OAuth2\Server\Storage\Adapter;
-use \League\OAuth2\Server\Storage\ScopeInterface;
-
-class ScopeStorage extends StorageAdapter implements ScopeInterface
-{
-    public function get($scope, $grant_type = null, $client_id = null)
-    {
-        $sql     = 'SELECT * FROM oauth_scopes WHERE id = ?;';
-        $results = $this->db->fetch($sql, [$scope]);
-
-        if (count($results) === 0)
-        {
-            return null;
-        }
-
-        return (new ScopeEntity($this->server))->hydrate([
-            'id'          => $result[0]['id'],
-            'description' => $result[0]['description'],
-        ]);
-    }
-}
-