bugfix: fix issue with push and pull returning the builder incorrectly

src/Jenssegers/Eloquent/Builder.php

+<?php namespace Jenssegers\Eloquent;
+
+class Builder extends \Illuminate\Database\Eloquent\Builder {
+
+    /**
+     * The methods that should be returned from query builder.
+     *
+     * @var array
+     */
+    protected $passthru = array(
+        'toSql', 'lists', 'insert', 'insertGetId', 'pluck',
+        'count', 'min', 'max', 'avg', 'sum', 'exists', 'push', 'pull'
+    );
+
+}
\ No newline at end of file

src/Jenssegers/Eloquent/Model.php

@@ -176,4 +176,15 @@ abstract class Model extends \Illuminate\Database\Eloquent\Model {
         return parent::newBaseQueryBuilder();
     }
 
+    /**
+     * Create a new Eloquent query builder for the model.
+     *
+     * @param  \Jenssegers\Mongodb\Query\Builder $query
+     * @return \Jenssegers\Mongodb\Eloquent\Builder|static
+     */
+    public function newEloquentBuilder($query)
+    {
+        return new Builder($query);
+    }
+
 }