Bug 1390517 - Travis: Reduce duplication in .travis.yml
Bug 1390517 - Travis: Reduce duplication in .travis.yml

All but one of the jobs is using `sudo: required`, so it makes more
sense to set it globally, and override on just that one job.

tojonmz/treeherder,tojonmz/treeherder,KWierso/treeherder,tojonmz/treeherder,tojonmz/treeherder,edmorley/treeherder,edmorley/treeherder,tojon/treeherder,tojonmz/treeherder,edmorley/treeherder,KWierso/treeherder,tojonmz/treeherder,KWierso/treeherder,tojon/treeherder,edmorley/treeherder,tojon/treeherder,KWierso/treeherder,tojon/treeherder