Introduced rpc_compat.create_connection()
Introduced rpc_compat.create_connection()

This will be used to emulate oslo-rpc API using oslo.messaging.

blueprint oslo-messaging

Change-Id: I2c1aa159132e4aad0138d4b0b7ff90eb98ed400c

citrix-openstack-build/neutron-fwaas,gaolichuang/neutron-fwaas,openstack/neutron-fwaas,openstack/neutron-fwaas,dougwig/x-neutron-fwaas,gaolichuang/neutron-fwaas