Test of renaming master branch to main

[abadger]

This is a test PR to make sure renaming branches is going to work.

[abadger]

This seems to be the way to change from master to main when there are just a small number of open PRs:

git clone repo
git checkout master
git pull --rebase
git checkout -b main
git push --set-upstream origin main  
# Go to github and retarget the open PRs to main
# Go to github settings and set the default branch to main
# Go to github settings and change any branch protection rules for master to be for main instead
# Go to github and delete the master branch
# Update any config that references the master branch.  For instance: https://github.com/ansible-community/antsibull/pull/100

Questions for more widely used/forked repos:

• Does something then need to be done to everyone's clones?
• Do we need to use git symbolic-ref to create an alias from master to main for a time?
  • https://stackoverflow.com/questions/14365946/git-branch-alias
• Retargetting PRs would be painful to do manually if there are a large number of PRs. Can this be scripted? Is there some other way to achieve the same thing?

[abadger]

Here's the api to change pr base branches https://developer.github.com/changes/2016-08-23-change-base/