Updated openstack/openstack
Project: openstack/taskflow  96a387f66f5d151259601b86047eec8eee72df6c

Move scheduler and completer classes to there own modules

To allow other components to more easily import these modules
without causing circular imports split these two classes into
there own modules so that they can be referenced as/where
needed in the future.

Change-Id: I9cf1fd1dd133be58ef521a8911d1740f1daa9950