create 10.8 branch:
- git checkout origin/10.7 -b 10.8 --no-track
- change VERSION (10.8.0-alpha)
- rename and change files in debian/
- find debian -name '*10.7*'
- grep -r 10.7 debian
- it's almost always s/10.7/10.8/ except in debian/control in Breaks/Replaces lists.
- buildbot config
- same, search for 10.7, replace with 10.8 or add 10.8 to the list, as needed
- git push origin HEAD:bb-10.8-release
- verify in buildbot that everything works
- git push --set-upstream origin HEAD:10.8
- change the default branch on github, enable branch protection