Update CONTRIBUTING.rst
Update CONTRIBUTING.rst

Change-Id: I695673d75a0d1388ffb149e35b2d3a59b70c4713

openstack/sahara-scenario,openstack/sahara-tests,openstack/sahara-scenario,openstack/sahara-tests,openstack/sahara-scenario,openstack/sahara-tests,esikachev/sahara-tests,openstack/sahara-tests,esikachev/sahara-tests,esikachev/sahara-tests