Tinyec

Be py3 compatible, thanks to byronrthomas.

What's Changed
* Make compatible with python3 by byronrthomas in https://github.com/alexmgr/tinyec/pull/3

New Contributors
* byronrthomas made their first contribution in https://github.com/alexmgr/tinyec/pull/3

**Full Changelog**: https://github.com/alexmgr/tinyec/compare/v0.3.1...v0.4.0

- Boring packaging changes
- Added MANIFEST.in to include license and readme files
- Renamed tests folder to test, so it is included automatically in release

- Added ECDH support
- Fixed packaging by adding MANIFEST.in file
- Better printing of parameters and curves
- Fixed bug in not-equal code

- Arithmetic on elliptic curves
- Most common curves added