Override 'savanna' strings in openstack/common

We are deferring a sync with oslo at this time, so the 'savanna'
references generated indirectly via the project name must be
changed manually.

Partial-Implements: blueprint savanna-renaming-service
Change-Id: I4d0fd9b12c288fcce7a15558c94f0199cfc90dac
Merge "Override 'savanna' strings in openstack/common"