Remove SMIRFF/SMIRNOFF and ChemicalEnvironment remnants from this repo

[jchodera]

We've now migrated the SMIRNOFF forcefield to a new repo:

http://github.com/open-forcefield-group/smirnoff

I was able to preserve commit history on all files that made the transition, though renaming smarty to smirnoff makes it harder to view this history in github.

Once that is stable, we should remove SMIRNOFF from this repo.

[davidlmobley]

Excellent, thanks, @jchodera !!

[jchodera]

Let's hold on this until I update the new repo according to our slack discussion.

[jchodera]

I have completed the bulk of the reorganization in https://github.com/open-forcefield-group/openforcefield. Please go there and comment/contribute PRs!

[jchodera]

We have now completed the migration to http://github.com/open-forcefield-group/openforcefield, so should remove SMIRNOFF and ChemicalEnvironment from this repo.

[davidlmobley]

Agreed. Just haven't had the time to do anything about it - still catching up after last week.

[bannanc]

I have this working on my local machine. I'm working on changing the travis settings so the tests on github will work.
See pull request #250

[davidlmobley]

Thanks, @bannanc .

[bannanc]

This was fixed in openforcefield PR#7