Bumped Python from 3.3 to 3.4

Because TravisCI now supports 3.4
Revert "Bumped Python from 3.3 to 3.4"

This reverts commit c265fb35d3abe42a2415e07dc269c6490e651841.
Added better test to job._add_missing_builds()
Merge pull request #277 from lechat/new_job_tests

Better tests for job._add_missing_builds()