mutual TLS
go run main.go \
--tls-cert certs/nwei-server.crt \
--tls-key certs/nwei-server.key \
--client-ca certs/nwei-ca.crt \
--port 8443
go run testclient/client.go \
--tls-cert certs/nwei-client.crt \
--tls-key certs/nwei-client.key \
--server-ca certs/nwei-ca.crt \
--url https://localhost:8443/healthcheck