Merge pull request #1968 from divine/fix_db_class_import

[fix] Correct import class for DB in Queue

src/Jenssegers/Mongodb/MongodbQueueServiceProvider.php

@@ -2,7 +2,7 @@
 
 namespace Jenssegers\Mongodb;
 
-use DB;
+use Illuminate\Support\Facades\DB;
 use Illuminate\Queue\QueueServiceProvider;
 use Jenssegers\Mongodb\Queue\Failed\MongoFailedJobProvider;