[Merge] lp:~barry/mailman/py3 into lp:mailman

The proposal to merge lp:~barry/mailman/py3 into lp:mailman has been updated. Status: Needs review => Merged For more details, see: https://code.launchpad.net/~barry/mailman/py3/+merge/245313 -- Your team Mailman Coders is requested to review the proposed merge of lp:~barry/mailman/py3 into lp:mailman.