tests: py.test removal from install requirements

[jirikuncar]

• Adds CONTRIBUTING.rst file.

[tiborsimko]

• Please add CONTRIBUTING.rst to MANIFEST.in.
• Please include it in docs/index.rst in the appropriate "Contributing" section to avoid duplicating this information.
• Hmm, have you looked at why Travis CI build fails during sphinx doc building? (I can build and test fine locally.)

[coveralls]

Coverage remained the same when pulling 1748810 on jirikuncar:pytest into 9d79630 on inveniosoftware:master.

[jirikuncar]

Please add CONTRIBUTING.rst to MANIFEST.in.

Added *.rst and docs to MANIFEST.in

Please include it in docs/index.rst in the appropriate "Contributing" section to avoid duplicating this information.

Done

Hmm, have you looked at why Travis CI build fails during sphinx doc building? (I can build and test fine locally.)

No clue. Now it should be ok. (https://travis-ci.org/inveniosoftware/workflow/builds/34260823)

[coveralls]

Coverage remained the same when pulling 61fd21b on jirikuncar:pytest into 9d79630 on inveniosoftware:master.

[tiborsimko]

I see you added AUTHORS in this commit; this is good, but requires some more changes:

• please add Raja Sripada <raja.sripada@cern.ch> right after Roman; he worked on pickle and friends, see CHANGES.txt
• the formatting of AUTHORS section is broken, please use list for contributors
• the CONTRIBUTING section would be logically better placed just before the AUTHORS, i.e. after API, like in our other repositories e.g. http://dictdiffer.readthedocs.org/en/latest/

(WRT last point, I also planned to add LICENSE and CHANGES as well, but that'd be better part of another separate PR)