Add an admin tool to clone a revision between Phabricator instances

[La0]

I made that to copy any diff from the production instance on the dev instance, so i'm able to test comments & issues reporting without spamming anyone

$ python copy_diff.py 52765
Connected on source: https://phabricator.services.mozilla.com/api/
Connected on destination: https://phabricator-dev.allizom.org/api/
Loading revision 52765
Source revision is on repository mozilla-central
Found matching repository on destination as PHID-REPO-myz5mwsn6hrgkxn2ndos
Loading diffs for PHID-DIFF-alrlnuu3mn4ttmiver6v
Loading raw source diff 191621
Created new diff 2471 - PHID-DIFF-5xhvkrqy54ebrphqnmz5
Set diff properties
New revision created as https://phabricator-dev.allizom.org/D1535

And it worked 🎉

[marco-c]

Nice idea ;)