installation: latest h5py version

• FIX Releases constraint on using an old version of h5py that was anyway no longer available on PyPI.

• Also moves cython before h5py so that h5py can be compiled.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>