release 3.1.0 into develop

[hardbyte]

No description provided.

[gpotter2]

Hi, we're seing all our linux tests fail since this came out :/ (we use python-can on secdev/scapy)

https://travis-ci.org/secdev/scapy/jobs/497744421

any ideas ? It looks like a requirements issue (should I open an issue? thanks !)

Collecting windows-curses (from python-can)
  Could not find a version that satisfies the requirement windows-curses (from python-can) (from versions: )
No matching distribution found for windows-curses (from python-can)

It might also be a temporary Travis bug, those happen, I will check that in details

[felixdivo]

That is strange, since the relevant file has not changed ... But yeah, please open an issue. Maybe others have also noticed it and have a fix.