Revert "ironic-python-agent is actually branchless"
Revert "ironic-python-agent is actually branchless"

This reverts commit c90e21af0a4b0c2b3a80f614eae0d00a365c1fa1.

Turns out that i-p-a master depends on oslo.service newer than
Liberty version which breaks tripleo-ci:
https://bugs.launchpad.net/tripleo/+bug/1550772

javierpena/rdoinfo,hguemar/rdoinfo,redhat-openstack/rdoinfo