Fix compatibility with Python 3.4
Fix compatibility with Python 3.4

reimandlab/Visualistion-Framework-for-Genome-Mutations,reimandlab/Visualisation-Framework-for-Genome-Mutations,reimandlab/ActiveDriverDB,reimandlab/Visualistion-Framework-for-Genome-Mutations,reimandlab/Visualistion-Framework-for-Genome-Mutations,reimandlab/ActiveDriverDB,reimandlab/Visualisation-Framework-for-Genome-Mutations,reimandlab/ActiveDriverDB,reimandlab/Visualisation-Framework-for-Genome-Mutations,reimandlab/Visualisation-Framework-for-Genome-Mutations,reimandlab/ActiveDriverDB,reimandlab/Visualisation-Framework-for-Genome-Mutations,reimandlab/Visualistion-Framework-for-Genome-Mutations