Make sure the name in setup.cfg is murano-agent not muranoagent

This also reverts the following oslo-incubator commit
https://github.com/openstack/oslo-incubator/commit/f6a1848688483c34be2fb5ba2544f80bc659a26c

Change-Id: I467699eb70c5332d097b072e6696cb21f6c6de63
Closes-bug: #1367543