fix setup.py issues

[JulienGrv]

I had issues with the setup.py that I fixed here.

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [x] I have read the CONTRIBUTING document.
• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] I have added tests to cover my changes.
• [x] All new and existing tests passed.

[coveralls]

Coverage remained the same at 75.842% when pulling 73b85bbe3c1a3970d6fb30bf0c0c89fed53f2b0a on JulienGrv:bugfix/fix-setup-problem into bb4c258849d22cc7f46cadaa1a0100c2da385ea5 on christoph2:master.