Add JOscProb tools and interactive sliders for oscillation probabilities

This addition brings some tools from JOscprob from Jpp to jppy, made by me and @bjjung . In particular the oscprobinterpolator, which interpolates over the 6 oscillation parameters, the energy and the zenith angle to calculate oscillation probabilities. By using Pybind11 this is implemented for python as well. On top of that there is a jupyter notebook, examples/interactive_oscprob.ipynb, which lets the users change the values of the oscillation parameters, the zenith angle and the energy and shows the effect on the oscillation probabilities. This can give physicists a more intuitive understanding of the impact of the parameters.