SciTools/iris — pull request #1153 by pelson (2014-06-03 09:55:44+00:00)
Title: Fixed travis build

It seems the stable PPA for ubuntugis has been broken, so I've moved it to the unstable build, which fixes it...

Cartopy has been using the unstable build for a few months without any noticeable interruptions (though obviously bandwidth is lower), and it is easy enough to revert back to the sable build once it has been fixed.