Adding multiclass

.travis.yml

Code/MonoMultiViewClassifiers/ExecClassif.py

Code/MonoMultiViewClassifiers/utils/Multiclass.py

Code/MonoMultiViewClassifiers/utils/execution.py

Code/Tests/Test_utils/test_execution.py

Code/Tests/Test_utils/test_multiclass.py

Code/Tests/test_ExecClassif.py