* Replace .testr.conf by .stestr.conf for migration and update
.gitignore, test-requirements.txt and lower-constraints.txt
files accordingly
* Use py3 as the default runtime for tox and 3.18.0 as the
minversion for tox
* Add a new job, openstack-cover-jobs, to run the coverage in Zuul
Change-Id: If6fa3f2f861d5eb6787743edcc6333e5aacef7d0
Add oslo modules which we will need for tests implementation. Also
add base class for tests, tox instruction for coverage and changes
to dot files.
Change-Id: Ia105f1e5e088ee91ce4b30149d4721df81d28368