This works around a frequent problem we've been having with Travis
CI's apt repository being busted on startup. This, in turn, caused
`apt-get install moreutils` to fail.
We attempt to fix this by adding our own retry logic.
This directory contains scripts that are used in building, managing,
testing, and other forms of work in a Zulip development environment.
Note that tools that are also useful in production belong in
scripts/ or should be Django management commands.