Drop use of deprecated collections classes
Drop use of deprecated collections classes

These were moved in Python 3.3 and the aliases will be dropped in 3.10.

Change-Id: I98985aef57ebe024e97e444ffd0d43ee2b88b332
Signed-off-by: Stephen Finucane <4725dc7f3632bf126d9fbdc30c347e91e8d2fe16@redhat.com>

openstack/oslo.cache,openstack/oslo.cache