Add support for pyup.io

[whimboo]

Pyup.io can be used to stay up2date with dependencies. It will automatically issue pull requests with details about news in that version. See mozilla/PyPOM#17 for example.

[whimboo]

This is finally done now given that I totally missed to do it in all the last months. The initial PR from pyup.io is here: #448

[whimboo]

@davehunt, as it looks like pyup.io only proposed updates for the packages as required for tox. What would we have to change so it also checks the mozdownload dependencies?

[davehunt]

@whimboo see the discussion in pyupio/pyup#137

[whimboo]

Ok, so that means we would have to create a requirements.txt file with the list of packages and versions, and read it inside of setup.py. We already do that for various other projects, so that shouldn't be a complex change. For example check: https://hg.mozilla.org/mozilla-central/file/default/testing/marionette/client/setup.py#l48

@Nebelhom would you be interested to make this change?

[Nebelhom]

Hi @whimboo Thanks for highlighting. I will give it a go.

[whimboo]

I merged PR #450. Thank you a lot Johannes! Lets see how it works...