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.
As part of extracting this, we exempt the library from all custom
checks on itself. This is expedient, since a lot of our
custom checks are naive about whether things are in strings, and
it is also a pain to configure individual rules.
In this commit we start to check for violations to PEP-E261 in our
codebase by default in our linters. Also we have introduced a
ignore list which has around 20 files still in violation to
PEP-E261 which we intend to clear up soon.
The only thing being translated in any email was the title of the Zulip
header image in the html file, probably because not doing so breaks a linter
rule.
he name "Zulip" doesn't make sense to translate anyway.
We've found a couple major issues that we need to fix:
* TRAVIS_COMMIT_RANGE being computed incorrectly in some cases (?!)
* The imperative linter could use some work.