Remove the __init__ method from the test action
Remove the __init__ method from the test action

This wont be needed once mistral-lib provides one.

Change-Id: If47672f54e7158c9fd8f144ed69588ebed05511a
Depends-On: I7cf9fdc9446462c7f5010d0ba8b307b05656704e

openstack/mistral,StackStorm/mistral,StackStorm/mistral,openstack/mistral