Switched 404 URLs to point to PyPI
Switched 404 URLs to point to PyPI

I noticed that your badges were pointing at `https://img.shields.io/pypi/pyversions/typedjsonrpc`, which returns a 404. Most other repos that use shields.io make their badges link to their package on PyPI ([example](https://github.com/tartley/colorama/blob/master/README.rst)), so that is what I did,
palantir/typedjsonrpc,palantir/typedjsonrpc