Fix contributing.rst file
Fix contributing.rst file

Fixes: bug #1205474

Change-Id: Ia045201c51f7067d18102aee768d46028b6eb0d2

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