Log Message:
py-zmq: updated to 17.1.0

17.1.0:
- Bump bundled libzmq to 4.2.5
- Improve tornado 5.0 compatibility
  (use :meth:~tornado.ioloop.IOLoop.current instead of \ 
:meth:~tornado.ioloop.IOLoop.instance
  to get default loops in :class:.ZMQStream and :class:.IOLoopAuthenticator)
- Add support for :func:.curve_public
- Remove delayed import of json in send/recv_json
- Add :meth:.Authenticator.configure_curve_callback
- Various build fixes
- sdist sources generated with Cython 0.28.3
- Stop building wheels for Python 3.4, start building wheels for Python 3.7