Mailman Web

• Postorius bumped to 1.2.3 release
• Images now use alpine:3.8 release instead of python:alpine-3.6 release, this was done so that we can use apk packages compiled against Python in alpine. Contributed by Patrick Georgi.
• Xapian is now added as a part of the Mailman-web container image. Contributed by Patrick Georgi.
• Bumped MailmanClient to 3.2.1 and Django 2.1.5
• Upgrade Hyperkitty to 1.21 release.

Mailman Core