Update README for project move.
Update README for project move.

* README.md: Correct .gitreview sample and Github URL.

Change-Id: I6aa23a54c3acd756141777513867d49873355027

jeeloo/git-review,meelapshah/git-review,entropia1/git-review,ka2m/git-review,meelapshah/git-review,openstack-infra/git-review