Allow just specifying 'workers' for WBE entrypoint

Instead of requiring and only finding 'worker-based' just
instead add the ability to use 'workers' as the addition
of '-based' doesn't add much value and isn't really that
beneficial/useful to have to type/require.

Change-Id: Icacb933e87147e421589457338d13fd8d59e0e55

doc/source/engines.rst

@@ -182,10 +182,10 @@ using your desired execution model.
     :pybug:`22393` and others...) as the most recent python version (which
     themselves have a variety of ongoing/recent bugs).
 
-Worker-based
-------------
+Workers
+-------
 
-**Engine type**: ``'worker-based'``
+**Engine type**: ``'worker-based'`` or ``'workers'``
 
 .. note:: Since this engine is significantly more complicated (and
           different) then the others we thought it appropriate to devote a

setup.cfg

@@ -51,6 +51,7 @@ taskflow.engines =
     serial = taskflow.engines.action_engine.engine:SerialActionEngine
     parallel = taskflow.engines.action_engine.engine:ParallelActionEngine
     worker-based = taskflow.engines.worker_based.engine:WorkerBasedActionEngine
+    workers = taskflow.engines.worker_based.engine:WorkerBasedActionEngine
 
 [nosetests]
 cover-erase = true