tag cleanup

[dkg]

i was just looking at the tags on
https://github.com/getdnsapi/getdns-python-bindings, and i see that most
of the release tags look like v0.3.1 (with the leading "v"). however,
0.2.0 and 0.2.1 are exceptions to this rule (probably by accident).

You should be able to fix this with:

  git tag v0.2.0 0.2.0
  git tag v0.2.1 0.2.1

I also notice that the tags on this repo are not signed. For
verification purposes, it'd be great to have the release tags explicitly
signed, and make clear what keys the project expects to do the signing in the future.

[MelindaShore]

This is an excellent suggestion. We'll work out keying details and I'll close out this ticket once it's done.