auth-service manages user-service and token-service via their own feign clients (modules: user-client, token-client)
- Users can only have one account
- openssl genrsa -out keypair.pem 2048
- openssl rsa -in keypair.pem -pubout -out public.pem
- openssl pkcs8 -topk8 -inform PEM -outform PEM -nocrypt -in keypair.pem -out private.pem