Enable swift payload upgrades for wallaby+

Sync charm-helpers to pick up fix for openstack_upgrade_available
that enables successful payload upgrades. This will need backporting
to stable/wallaby.

The openstacksdk version is pinned in test-requirements.txt to enabled
py36 unit tests to run successfully.

https://github.com/juju/charm-helpers/pull/871
Closes-Bug: #2040606
Change-Id: I1c6a8adaf61f927239aeecbcd7cde28e47885b20

charmhelpers/contrib/openstack/utils.py

@@ -409,16 +409,6 @@ def get_os_version_codename(codename, version_map=OPENSTACK_CODENAMES):
     error_out(e)
 
 
-def get_os_version_codename_swift(codename):
-    '''Determine OpenStack version number of swift from codename.'''
-    for k, v in six.iteritems(SWIFT_CODENAMES):
-        if k == codename:
-            return v[-1]
-    e = 'Could not derive swift version for '\
-        'codename: %s' % codename
-    error_out(e)
-
-
 def get_swift_codename(version):
     '''Determine OpenStack codename that corresponds to swift version.'''
     codenames = [k for k, v in six.iteritems(SWIFT_CODENAMES) if version in v]
@@ -843,10 +833,6 @@ def openstack_upgrade_available(package):
     if not cur_vers:
         # The package has not been installed yet do not attempt upgrade
         return False
-    if "swift" in package:
-        codename = get_os_codename_install_source(src)
-        avail_vers = get_os_version_codename_swift(codename)
-    else:
     try:
         avail_vers = get_os_version_install_source(src)
     except Exception:

test-requirements.txt

@@ -37,6 +37,10 @@ stevedore<1.31.0;python_version<'3.6'
 debtcollector<1.22.0;python_version<'3.6'
 oslo.utils<=3.41.0;python_version<'3.6'
 
+# New openstacksdk versions depend on platformdirs>=3 which does not support
+# python 3.6
+openstacksdk<1.6.0; python_version <= '3.6'
+
 coverage>=4.5.2
 pyudev              # for ceph-* charm unit tests (need to fix the ceph-* charm unit tests/mocking)
 git+https://github.com/openstack-charmers/zaza.git@stable/wallaby#egg=zaza