Breakout Changelog, Create Github Templates

[hydrosquall]

These changes aren't essential but would shorten the core README.md. The Templates would increase the odds that new Issues and PRs filed adhere to a format that the development team would find more useful, potentially saving time and energy for everyone involved in the process.

• Breakout a new CHANGELOG.md from the README.md
• Add a basic ISSUE_TEMPLATE and PULL_REQUEST_TEMPLATE based on the existing contributions and common practices in the open source community

If these changes sound useful for the project, please let me know in this thread, and I'd be happy to make them.

[tbarn]

Hey @hydrosquall!

I'd be happy to make this work part of Hacktoberfest. Also, including a link to the changelog in the readme would be nice.

Issue and pull requests templates have been on my list of things I'd like to have. If you want to try your hand at one (maybe similar to the JavaScript SDKs one), I'd be happy to collaborate with you on it.

[hydrosquall]

@tbarn - sounds great! I'll put something together and push it up shortly.

On a separate note, how would you feel about having a PyPI badge added to the docs showing the current library version (next to the build badge)?