Release v2.0.0

- Add sampling app with improved command-line interface for uniform
sampling
- Replace HDF5 Backend with HighFive for stable HDF5 parsing
- Add FindSBML
- Restructure thirdparty headers
- Update FindGurobi
- Update Readme
- Replace Google Test by Boost unit tests. This should speed up
building.
- Fix small bug in csvreader
- Move examples to bin