Small fixes to show_upgrade_diffs (#1473)
Small fixes to show_upgrade_diffs (#1473)

* Small fixes to show_upgrade_diffs

- fix fetch for an existing directory (we can't fetch to local "master"
  branch, use "origin/master" instead).
- add a newline after "removed" entries.

google/nomulus,google/nomulus,google/nomulus,google/nomulus,google/nomulus,google/nomulus