previously disable the cache update was only possible on ubuntu
using the generic name wireguard_update_cache it can be enabled for all
operating systems
* move register if config/private key handling out of wg subcommands block
* allow user to specify WireGuard interface restart behavior
* update README
* numeric values in meta/main.yml should be strings
* update Copyright
* fix indentation in tasks/setup-debian.yml
* update Copyright
* update Copyright
* truthy values should be lowercase
* add namespace key again to meta/main.yml
* add molecule/kvm/verify.yml with a very basic unit test