prepare-to-hack-on-openstack.md

When you have a lot of throw away environments you will need to add SSH key often, details to script are here:
https://dev.vaadin.com/review/Documentation/cmd-set-account.html

Example:

cat ~/.ssh/id_watcher.pub | ssh -p 29418 review.example.com gerrit set-account --add-ssh-key - --add-email mail@example.com watcher