Fix master branch (and switch to pytest)

[ticosax]

No description provided.

[ticosax]

@jettify I'm interested to maintain this project. Would you like to transfer ownership to my account or to an organization like https://github.com/jazzband/ ?

[coveralls]

Coverage decreased (-1.3%) to 98.718% when pulling a9e409d on ticosax:fix-tests into c60f732 on jettify:master.

[coveralls]

Coverage decreased (-1.3%) to 98.718% when pulling a9e409d on ticosax:fix-tests into c60f732 on jettify:master.

[jettify]

@ticosax I probably move aiohttp_sse to https://github.com/aio-libs, since most of my projects live there, jazzband looks more Django oriented. So if you still have interest, I think we can figure out something there

(cc @asvetlov )

[ticosax]

@jettify transferring the project to aio-libs is fine with me.
FYI Jazzband is focused on python, not only django, so aiohttp_sse could be accepted.
Note also that publishing of releases to pypi is done automatically with jazzband.
That's something that is worth considering, otherwise you will end up doing administrative tasks to grant access to pypi for maintainers.