publish on melpa

[wbolster]

melpa/melpa#5286

[thomas-louvigne]

Don't forget the licence file.

[wbolster]

it's in the readme already:

https://github.com/wbolster/emacs-python-pytest/blob/master/README.rst#license

[wbolster]

update: addressed some reviewer comments from @purcell: melpa/melpa#5286 (comment)

[wbolster]

https://melpa.org/#/python-pytest 🎉