Comment 3 for bug 1134428

There is code in tarmac as a plug-in which already does this. https://bazaar.launchpad.net/~tarmac/tarmac/main/view/head:/tarmac/plugins/allowedcontributors.py

It allows specifying any team or person on launchpad in the tarmac.conf as an allowed contributor, on a per-target-branch basis.