Feature/parallel

There is a new folder kepler-c-parallel with the parallel computation. In the notebook there is the complete vectorize function, a serialized version of the last vectorization and a parallel version of that last. There are prints to check the times and to check that the results are the same. The notebook has to be modified to resemble the rest of the examples. The current status will help to check its understanding and to check if it works. It uses the f2py functions, but it should work as well with jit compilation