app/mailman-web: create

There's a lot of ugly hacks here, but this has been the state of prod
for months now, so we should reflect that.
Also, this bumps a bunch of workspace deps.

Change-Id: I744e0d3aff27036cfed73416cf442c7d62444a8b
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1473
Reviewed-by: q3k <q3k@hackerspace.pl>
diff --git a/app/mailman-web/upstream_settings/README b/app/mailman-web/upstream_settings/README
new file mode 100644
index 0000000..9700643
--- /dev/null
+++ b/app/mailman-web/upstream_settings/README
@@ -0,0 +1 @@
+Unmodified copy of default settings from mailman-web.