Initial implementation of the plugin
We actually don't use NSS

That was from earlier attempts...
Remove useless logs

That was from earlier debugging...
Don't check something that can't happen

There's just no way Koji will call us for something else.

And even if it did, the parameters wouldn't make any sense.
This is not an error

It merely is something we choose to ignore.
Don't setup the logging

Turns out, we don't log anything any more. :-/

We can always add it back if needed.
Read the config file
Make the tags configurable
Make the signing command configurable
Sanitize the environment before running the sign command
Rename the config file
Add a simple Makefile