hkp4py hkp|hkps bindings for python.

[Vincent Breitmoser]

Hi Marcel,

thanks for working on VKS support :)

> Can someone look into it. I am currently curious if it breaks current stuff.
> https://github.com/Selfnet/hkp4py/tree/feature/gpg-vks

Looks good to me, only remarks I have is you probably don't need to quote the
key id, and the "host" variable should be called "baseURI" or something, "if not
host.startswith("hkp"):" looks odd. On that last bit, checks like that should
always include the :, you don't want to match an "hkpkpkp" schema.

The "vks" schema is kind of an informal thing that comes from Enigmail.
I wonder if we should adopt it (slightly) more formally in our API docs.

> I also want to know if hkp4py`s further releases need to support python
> 2.7.x and python 3.5.x and older.

python2 is EOL, and projects that still rely on it shouldn't invest development
time into anything other than fixing that.

Cheers!

 - V