Till now, zhmcclient is installed from github master branch using
pip. As zhmcclient is now an official OpenStack requirement [1]
We can switch to install the latest stable version via
requirements.txt.
To allow newer versions in the future, an update to the
upper-constraints.txt in the OpenStack requirements repo is
required.
To bump the minimum just increase the version in requirements.txt
of nova-dpm and make sure, that newer versions are allowed
by OpenStack requirements (see above).
[1] https://review.openstack.org/413689
Change-Id: I0da5f9271ee3391a4648064207eab5b4fb7e26fb
Closes-Bug: #1655905
28a7038550