controller: Start scheduler jobs with app_name metadata

Signed-off-by: Lewis Marshall <lewis@lmars.net>
controller: Stop the newest jobs when scaling down

Signed-off-by: Lewis Marshall <lewis@lmars.net>
test: Exit on failure in TestBasic

Signed-off-by: Lewis Marshall <lewis@lmars.net>
Merge pull request #398 from flynn/controller-fixes

Controller fixes