Throw ValueError which results into 400 status code if user doesn't provide resource id / name / ref.
Throw ValueError which results into 400 status code if user doesn't provide
resource id / name / ref.

Previously internal server error was returned.

armab/st2,Plexxi/st2,dennybaa/st2,StackStorm/st2,punalpatel/st2,Plexxi/st2,StackStorm/st2,dennybaa/st2,lakshmi-kannan/st2,emedvedev/st2,nzlosh/st2,Plexxi/st2,peak6/st2,tonybaloney/st2,punalpatel/st2,armab/st2,pixelrebel/st2,nzlosh/st2,emedvedev/st2,StackStorm/st2,nzlosh/st2,tonybaloney/st2,pixelrebel/st2,peak6/st2,punalpatel/st2,peak6/st2,nzlosh/st2,dennybaa/st2,armab/st2,Plexxi/st2,lakshmi-kannan/st2,StackStorm/st2,tonybaloney/st2,pixelrebel/st2,lakshmi-kannan/st2,emedvedev/st2