release 2.0.3

bump version

bump to 2.0.1

include test files in source release

post-release fix for conda

fix py3dmol save snippet

Merge pull request #100 from chemosim-lab/black-formatting

* Reformats the entire codebase with `black` and `isort`
* Refactors some of the reused test objects as fixtures in the conftest file
* Adds the `VdWContact` interaction to the defaults, and changes the `tolerance` parameter to 0
* Fixes issue #89 caused by an empty `fp.ifp` object

fix setup script

fix citation formatting

add versionchanged note