Updated openstack/openstack
Project: openstack/python-ceilometerclient  d35a2d94443fecc49741eb77ee4fb378bcf09653

Add `requests` to requirements

This library is used by default for all HTTP calls, so it should be in
requirements of ceilometerclient.

Change-Id: I298f1d6279c5bb9d4ed85760f2fdba00c4c3ada9