Branch is broken so we need 2 fixes:
1) Add upper-constraints.txt from stable/newton
This will be used to set the upper-constraints for unit
test jobs on this branch.
2) Backport "Remove usage of parameter enforce_type"
oslo.config has deprecated the enforce_type parameter to
set_override() and set its default value to True [1],
so remove this usage from our codebase. Also remove
explict str() cast of mock.sentinel_password in
Windows driver since it should no longer be expected.
[1] Ifa552de0a994e40388cbc9f7dbaa55700ca276b0
(cherry-picked from 4e25ce5a0c)
Change-Id: Id7db496441f6c1d620a4995812ed4f8c98a00ad5
cb76d2febc