The OpenStack API working group recommends all projects adopt
Nova-style microversions for versioning their REST APIs. This
commit ports the Nova microversion code and docs to Manila.
With this patch, the API version is bumped to 1.1, and the
versions API (which has always returned horribly outdated
values) is the first API that is versioned. The 1.1 version
of the versions API includes the minimum and current API
version values.
Implements bp: manila-rest-api-microversions
Change-Id: Ifa8e394335a4eb3ad21f53a873530aee241c00e8