Related to #109, removal of redundant file process_files.py and check_data refactoring

[nickkprice]

• Removed redundant file process_files.py
• I think check_data is valuable it just needs to be scripting friendly
• Reformatted check_data to be runnable from user file, e.g:

import fit_resonator.check_data as cd

cd.file(path_to_data_file) or cd.raw(frequency, magnitude, phase)

-Updated README to reflect change Also, I'll keep a local copy of process_files in case the logic is useful