Foyer

Attention
The `lark-parser` package recently updated to version 0.8.6, which has broken certain SMARTS functionality within foyer. Until these issues are resolved, do not use `lark-parser` version 0.8.6. This has been hotfixed until the issue has been resolved (337)

Features
- Automate Docker Image publishing with AZP (334)
- Add OPLS SMARTS strings for Sulfur Compounds (307)
Bug Fixes
- Pin lark-parser to version 0.8.5 (337)

Features
- Add version attribute to ForceField class and XML schema (298)
- Expand OPLS-AA XML coverage:
- Amides (278)
- Isopropyl and tert-butyl ether (311)
- Chlorobenzene and benzonitrile (308)
- Methyl-nitro aniline (319)
- Secondary and Tertiary alcohols (320)
- Update to use smaller files for testing (313)
- Remove OpenMM from atom-typing step (296)

Maintenance
- Fix travis by not installing md5sha1sum (302)
- Refactor unit tests to use mbuild recipes instead of mbuild examples (303)
- Remove six from requirements (325)
- Drop Appveyor YML and update README (329)

Miscellaneous
- Add LICENSE.rst to MANIFEST.in (324)
- Build documentation on ReadTheDocs (316)

Features
- Establish entry points for external force fields (282)
- Separate parametrization step into a discrete function (294)

Bug Fixes
- Reorder `_check_angles` function in order for `verbose` messages to be printed (293)
- Fix TravisCI build errors (300)
- Pass `assert_improper_params` argument to `parametrize_system` (299)

Miscellaneous
- Remove coveralls badge from README (289)
- Switch force field entry points to functions that load classes (288)

Features
- Add Azure Pipelines for CI (273)
- Mock requests in unit tests for reference retrieval (283)

Bugfixes
- Handle failures of retrieving BibTeX references with a warning (276)
- Set default combining rule to geometric (285)

Miscellaneous
- Add style fixes suggested by LGTM (274)

This is a hotfix release to ensure compatibility with NetworkX 2.x (up to at least 2.4).

Fixes

* Update `atomtyper.py` to use methods of NetworkX 2.x, (280)