add logging statements to microservice

[mtbc]

The Configuration class uses SLF4J to log some errors. Logging could be added more generally throughout the server code.

[joshmoore]

I'd also note the likes of https://github.com/romanpierson/vertx-web-accesslog ... or perhaps more simply https://vertx.io/docs/apidocs/io/vertx/ext/web/handler/LoggerFormat.html