Fix for getting next available job, v2

Update the underlying PHP client call to return a new document instead of the one before.

Fix for getting next available job

Updates query within getNextAvailableJobAndMarkAsReserved to match query from getNextAvailableJob.

Fix for atomic operation

This fixes an issue with failed jobs not being removed from the jobs queue.

Laravel 5.3+ support

The queue implementation has been updated for Laravel 5.3+ to support the latest changes to the underlying DatabaseQueue.

Initial Packagist release

Thread-safe MongoDB database queue implementation for Laravel