Apparently, we've now had the first time one of our contributors had
their account deleted (at least, the author page for the contributor
who has 21 commits in python-zulip-api now 404s).
Tweaked by tabbott to not remove it from lister.py, linter_lib, and
friends, since those are intended to support both Python 2 and 3
(we're planning to extract them from the repository).
This causes `upgrade-zulip-from-git`, as well as a no-option run of
`tools/build-release-tarball`, to produce a Zulip install running
Python 3, rather than Python 2. In particular this means that the
virtualenv we create, in which all application code runs, is Python 3.
One shebang line, on `zulip-ec2-configure-interfaces`, explicitly
keeps Python 2, and at least one external ops script, `wal-e`, also
still runs on Python 2. See discussion on the respective previous
commits that made those explicit. There may also be some other
third-party scripts we use, outside of this source tree and running
outside our virtualenv, that still run on Python 2.
This adds the authors to the Zulip repository on GitHub from
/authors/ along with re-styling the page to fit the same
aesthetic as /for/open-source/ and other product-pages.
This helps make the Zulip development environment somewhat more robust
to new contributors, since it will give them a nice warning if they
try running any of our development tools outside the Zulip virtualenv.
Fixes#3468.
Contributor visualization showing the avatar, user name and number
of commits for each contributors. The JSON data would be updated
upon deployment, triggered by the `update-prod-static` script.
