Get process_components_cif_cli working in refactoring branch

Issue #38 (closed) Add process_components_cif script to back refactoring branch in stub form now finished.

So functionality developed and tested in milestone %Improve PDBe Chemical Components backend infrastructure using RDKit: beta test version can now be added back to refactoring branch using the unit test test_process_components_cif_cli.py taken from current master.