v6.1.0

• :pr:67: Refactor testsuite to completely rely on pytest.

  • Integrate pytest-testmon and pytest-watch

  • Stabilise testing

• :cp-issue:1664 via :pr:66: Implement input termination flag support as
  suggested by @mitsuhiko <https://github.com/mitsuhiko>_ in his
  wsgi.input_terminated Proposal <https://gist.github.com/mitsuhiko/5721547>_.

• :issue:73: Fix SSL error bypassing.

• :issue:77 via :pr:78: Fix WSGI documentation example to support Python 3.

• :pr:76: Send correct conditional HTTP error in helper function.

• :cp-issue:1404 via :pr:75: Fix headers being unsent before request
  closed. Now we double check that they've been sent.

• Minor docs improvements.

• Minor refactoring.