Merge branch 'release/0.4.7' into develop
PyContracts dependency PyParsing needs version 2.0.0 to work with Python 3 but this version doesn't work with Python 2.
0.4.8:
    PyContracts dependency PyParsing needs version 2.0.0 to work with Python 3 but this version doesn't work with Python 2.
Merge branch 'release/0.4.8'