Remove automagic requirements.txt.
Remove automagic requirements.txt.

This works, but for git-review it's actually just extra
overhead, rather than being helpful.

Change-Id: Ic39855ae7bb9ce47afe5db2f5ecc2dac2f36b73b

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