When proposing the patch [1] to retire panko deliverables in governance
repository, the validator fails as there should be only .gitreview and
README.rst in the retired repository. This patch cleans up .gitignore
file to make the validator pass.
[1] I0bec371f442c4e39557bf1f0d94697e1577bb838
Change-Id: I5cc65714c6e0eaf835d321f4dd48501167182568