Cleaned up Travis config.
Cleaned up Travis config.

jeffreybaird/oga,YorickPeterse/oga,altmetric/oga,ttasanen/oga,YorickPeterse/oga,YorickPeterse/oga,ttasanen/oga,altmetric/oga,jeffreybaird/oga,dfockler/oga,jeffreybaird/oga,dfockler/oga,altmetric/oga,dfockler/oga,ttasanen/oga,ttasanen/oga,ttasanen/oga,jeffreybaird/oga,dfockler/oga,dfockler/oga,YorickPeterse/oga,altmetric/oga,YorickPeterse/oga,altmetric/oga,jeffreybaird/oga