Python 3 support?

[gygitlab]

Alpine has recently got rid of Python2, which is needed for this (awesome) script.

While this is workaround-able for now I was wondering if there was ever any plans to support Python 3?

[gdraheim]

The python3 compatibility had been intended from the start but it was missing actual testing.

I have updated the testsuite to allow for selection of a python3 interpreter, and the few errors are fixed now.

Please give it a test if it works for you.

[gygitlab]

Thanks @gdraheim. Had a check there and it still fails on this line - https://github.com/gdraheim/docker-copyedit/blob/master/docker-copyedit.py#L539

Looks like a missed except?

[gdraheim]

It did work on my disk but I did just notice that I had merged some patches that were created before modifying the master branch to Python3. The merge algorithm did somehow manage to revert one of the "except" usages. It is fixed now, thank's for checking that.

[gdraheim]

I have converted the source code to run with Python 3 by default. That includes the testsuite and I have added type hints.