* Allow configuring DNS cache
* Update sample configs
* Fix build errors
* Fix time resolution
* Default 5m
* In seconds
* Use WithDNScache
* Correct field name
* Update go.mod/go.sum to matrix-org/gomatrixserverlib#251
* Rename serverkeyapi to signingkeyserver
We use "api" for public facing stuff and "server" for internal stuff.
As the server key API is internal only, we call it 'signing key server',
which also clarifies the type of key (as opposed to TLS keys, E2E keys, etc)
* Convert docker/scripts to use signing-key-server
* Rename missed bits