Describe how to behave as a contributor

[pietermarsman]

I think it would help future contributors to participate if it is clear what we expect from them and what they can expect from the project. I'm thinking of the following:

• Use issues to point to problems
  • Discuss possible improvements in an issue
  • Include a minimal reproducible example if possible
  • Include the package version
• Use pull requests to fix problems
  • So no PR without an issue
  • Point your PR to the develop branch
  • PR's should be PEP8 compliant
  • PR's should create or update PEP257 docstrings if necessary.
  • PR's should include testing of the minimal reproducing examle if possible
  • PR's should work with python2 and python3 (for now)
  • PR's should succesfully run test-suite (on travis)

[tataganesh]

This is great! Thank you @pietermarsman !

[fakabbir]

Maybe this could have directly hit the master branch since CONTRIBUTIONS.md's reference is in master branch and the file is present in develop branch.

[pietermarsman]

Fixed by #259 and #304