ALL_USER_TYPES should be a tuple

turns out that 0.34.1.1+1 comes before 0.34.1.1+bionic (etc).

The version may only contain "~ 0-9 A-Z a-z + - ." (sorting in that order).

Option 1: replace "+" with something that sorts after +. Options are "-" (but
dpkg-source complains about that) or "." (but that would mean we couldn't
distinguish packaging-only changes from real changes).

Option 2: stick with + and just find something that sorts after 'xenial'. The
only options there are "-", "." (same problems as before), "z", and "+".

Hence, ++1. Sorry.

Rewrite this in python so that it can be run in parallel.

* Remove non-functional python3.6 in travis env

* changelog

Otherwise people can't upgrade from matrix-synapse without removing it first

Update README to use new virtualenv (#4328)

Fix spontaneous logout

Fixes #4371

This is already fixed in 0.34.1, by 59f93bb

This reverts commit efc522c5.

Fixup docstrings for matrixfederationclient

Use RequestSendFailed when fail to parse content type headers

Don't log stack traces for HTTP error responses