Add phase and count to variables passed in to playbooks

It would be nice to be able to show pre, run and post output separately,
but we need to know which of these things is happening so that the log
output can mark things appropriately. Pass in values so that zuul_stream
and friends can do something with them.

Change-Id: Iedb4f8504ce13dd8725685b6ef0bb3763675c218
1 file changed