bump version and add info for PyPI listing

[krisgesling]

Bump version number for release v0.3.7 Also added more info for the PyPI listing:

• README.md to be used as the long description
• basic classifier metadata

Description of how to validate or test this PR

• create package and run twine check

• [x] Whether you have signed a CLA (Contributor Licensing Agreement)

[forslund]

Looks good, let me verify a build and then I'll merge.

[forslund]

Package looks excellent. Merging