Added enqueue failure detection

If a job fails to be enqueued, it would be useful to know it.  So now
Resque actually tells us whether the enqueue action was successful or
if it failed.  If your job ID comes back as FALSE, it didn't enqueue.

Signed-off-by: Daniel Hunsaker <danhunsaker@gmail.com>
Updated to match coding style.

Signed-off-by: Daniel Hunsaker <danhunsaker@gmail.com>
Merge pull request #107 from danhunsaker/feature-queue-failure

Added enqueue failure detection