- Fix helm CLI download URL, the previous URL is no longer available,
and is superceded by get.helm.sh
- Fix jsonschema dependency spec, 4.x alpha versions were causing the
unit tests to fail for python 3.5
- Remove oslo.db dependency as it was not used and one of its recursive
dependencies (tempita) was failing during setup
Change-Id: I03e8a738bb8aad620903119638210077d211770c