Added the embryo of my unittests

Code/Exec.py

Code/MonoMultiViewClassifiers/ExecClassif.py

...ewClassifiers/Multiview/Mumbo/Classifiers/DecisionTree.py

Code/MonoMultiViewClassifiers/utils/execution.py

Code/Tests/Test_utils/__init__.py

Code/Tests/Test_utils/test_execution.py

Code/Tests/__init__.py

Code/Tests/test_ExecClassif.py

Code/Tests/test_poulet.py

Code/__init__.py