Before beginning each and every GCI task, you should do the following:
1. Fetch new commits from zulip/zulip (upstream):
$ git fetch upstream
2. Apply these new commits to your local master branch:
$ git checkout master
$ git rebase upstream/master
3. Create a new feature branch for your task:
$ git checkout -b task-<task-name> upstream/master
(Replace <task-name> with text describing which task you are are about to
start. Use hyphens - to separate words instead of spaces.)