Pastescript

------------------

* Open, read and write files in binary mode in copydir.py.
* Fix locking for modern Python.

------------------

* Pastescript is moved to https://github.com/pasteorg/pastescript

With version 3.6.0 pastescript development moves to the pasteorg GitHub
organization and will be going deeper into maintenance mode unless
more active maintainers step forward to take over. "Deeper" in this
case means that releases will be much less frequent and patches
will only be accepted for security issues or major problems. Current
consumers of pastescript should prepare to migrate away to more modern
solutions.

------------------

* Be explicit about Python 3 being required.

------------------

* Remove remains of Python 2 in code. Thanks to Alexandre Detiste (a-detiste)

------------------

* Correct working with PasteDeploy >=3. Thanks brondsem.

------------------

* Remove support for Python 2 in tests. It may still work outside tests.
* Fix homepage link. Thanks to Guillaume Gauvrit (mardiros).
* Stop using nose to run tests.
* Run tests in GitHub actions instead of travis CI.