- sync charmhelpers with fix-alpha helpers
- fix up code where the alpha comparisons are done
- fix tests which assumed mocks would just work on os_release()
Change-Id: Ifa495c37adeb24aa98e4e5e181b90cbbd5c0cddb
Related-Bug: #1659575
The charm-helpers project have re-licensed to Apache 2.0
inline with the agreed licensing approach to intefaces,
layers and charms generally.
Resync helpers to bring charmhelpers inline with charm
codebase.
Change-Id: I1b988a174d4a236599cffef8334a2923bf031fff