better way to set logging level across packages on startup
Our current method of setting up logging across all of our own packages is fragile and needs maintenance when we add/change package names:
https://github.com/AthanorLabs/atomic-swap/blob/3b4ae0224080b13046cf39ae059dc35f090264c4/cmd/swapd/main.go#L235-L241

An attempt was made to set the log level across all the packages using `"*"`, but that was pulling in lots of verbose logging from libp2p. This ticket is to research a solution and implement it.