requirements update for travis
requirements update for travis

guillermo-carrasco/TACA,SciLifeLab/TACA,kate-v-stepanova/TACA,kate-v-stepanova/TACA,SciLifeLab/TACA,SciLifeLab/TACA,vezzi/TACA,b97pla/TACA,senthil10/TACA,guillermo-carrasco/TACA,b97pla/TACA,senthil10/TACA,vezzi/TACA