implement basic save and load functionality

[orionarcher]

Description

Addresses issue #52

This PR seeks to implement basic functionality to serialize the key data in a Solution and then reconstitute it as a dict. This allows the main features of a Solution to be saved.

Todos

Notable points that this PR has either accomplished or will accomplish.

• implement Solution.load_json
• implement Solution.save_json
• clean up code
• finalize API

Status

• Ready to go

[pep8speaks]

Hello @orioncohen! Thanks for opening this PR. We checked the lines you've touched for PEP 8 issues, and found:

• In the file solvation_analysis/analysis_library.py:

Line 471:20: W292 no newline at end of file

[hmacdope]

You can use .__dict__() to compare internal state of two classes as dictionaries, might help in your comparisons.

[lilyminium]

This seems quite indirect -- why not have a to_dict, from_dict akin to a __setstate__, __getstate__ method?

save_json is also not my favourite method name. to_json could return a json string perhaps (json.dumps(obj.to_dict())), which the user could be responsible for writing to a file, or a to/from_file method could handle that.

With a bunch of common mis-matching APIs already out there (e.g. pandas.to_json, pandas.read_json; pydantic's .json(), .parse_raw/ .parse_file) keeping a neat to/from naming scheme is really valuable.