elfind.py and satid.py depend on v1_4 python-sgp4

Version string in Cythonized python-sgp4 was updated to   `version = '1.4_cython'` to distinguish it from the regular version.

Probably should update @interplanetarychris port of python-skyfield to accept this version and include it in the requirements.txt file

These utilities won't work in the default environment until that is fixed.

