Add qpid-python to requirements
Add qpid-python to requirements

Qpid is a supported messaging library, and without this it is
necessary to install it manually in order to use Qpid in some
environments, notably the one used by TripleO.

Change-Id: I398c1d35295223cbc6969b386129c6fc9acbefc7
Closes-Bug: #1225191

openstack/heat,maestro-hybrid-cloud/heat,gonzolino/heat,pshchelo/heat,steveb/heat,pratikmallya/heat,maestro-hybrid-cloud/heat,redhat-openstack/heat,takeshineshiro/heat,dragorosson/heat,ntt-sic/heat,rh-s/heat,takeshineshiro/heat,cryptickp/heat,noironetworks/heat,pratikmallya/heat,srznew/heat,rdo-management/heat,rh-s/heat,dims/heat,NeCTAR-RC/heat,NeCTAR-RC/heat,steveb/heat,jasondunsmore/heat,jasondunsmore/heat,ntt-sic/heat,miguelgrinberg/heat,cwolferh/heat-scratch,miguelgrinberg/heat,cwolferh/heat-scratch,rdo-management/heat,openstack/heat,noironetworks/heat,dims/heat,gonzolino/heat,pshchelo/heat,dragorosson/heat,redhat-openstack/heat,srznew/heat,cryptickp/heat