Following commits does several things:
* migrates CI of monasca-common to ostestr
* enables PY35 compatybility
Also:
* marked one tests as excluded under PY35 because changing
it would require affecting embedded kafka library which
will be eventually removed in future
(cherry-picked from commit cabc2ddd5f239e5f44e090d35aaac0770e5849ba)
Change-Id: I432a466e2620bc8d305ef2630307b636461c8e81