Pywincalc

- Exposed standards to python. Users can now interact with standards, methods, wavelength sets, etc...
- Exposed products to python.
- Changed thermal calcs back to just calc_u and calc_shgc. Users no longer need to call a specific method based on the input type. Now can pass either measured data format and the library will handle it.

Added the ability to use json data from igsdb.herokuapp.com as measured product data.
- Changed calc_u and calc_shgc to calc_u_optics_file, calc_u_shgc_file, calc_u_json_data and calc_shgc_json data. So user is responsible for selecting the correct function based on the data source.

Initial public release with example product files (optics format).