Remove resolver, fixes #451

src/Jenssegers/Mongodb/Model.php

 <?php namespace Jenssegers\Mongodb;
 
+use DateTime, MongoId, MongoDate, Carbon\Carbon;
+use Illuminate\Database\Eloquent\Relations\Relation;
 use Jenssegers\Mongodb\DatabaseManager as Resolver;
 use Jenssegers\Mongodb\Eloquent\Builder;
-use Illuminate\Database\Eloquent\Relations\Relation;
 use Jenssegers\Mongodb\Relations\EmbedsOneOrMany;
 use Jenssegers\Mongodb\Relations\EmbedsMany;
 use Jenssegers\Mongodb\Relations\EmbedsOne;
 
-use Carbon\Carbon;
-use DateTime;
-use MongoId;
-use MongoDate;
-
 abstract class Model extends \Jenssegers\Eloquent\Model {
 
     /**
@@ -35,13 +31,6 @@ abstract class Model extends \Jenssegers\Eloquent\Model {
      */
     protected $parentRelation;
 
-    /**
-     * The connection resolver instance.
-     *
-     * @var \Illuminate\Database\ConnectionResolverInterface
-     */
-    protected static $resolver;
-
     /**
      * Custom accessor for the model's id.
      *