message: Switch to `git` protocol for CI dependencies
  If you try to clone a repo that doesn't exist via `https`, `git` will prompt for
  auth credentials and hang forever. Using `git` avoids this and fails immediately
  instead, which is what we want for a missing repo.
  Part of
diff: @@ -17,7 +17,7 @@ clone() {
  if [ -n "$branch" ]
  then
  echo "Trying to use $org/$repo#$branch"
  - git clone https://github.com/$org/$repo.git $repo --branch "$branch" && exit 0
  + git clone git://github.com/$org/$repo.git $repo --branch "$branch" && exit 0
  fi
  }
  