Add logging to SOAP HRS URL DAO and update unit test

 * Updates the unit test to include the three new URL keys in #8 .
 * Adds `INFO` level logging to the SOAP implementation of the HRS URL DAO to help with troubleshooting whether the URLs are being read properly in a given deployment environment.  Unit tests the underlying log message composition.

This shouldn't result in an overwhelming amount of noise in the logs since the DAO refreshes only infrequently, what with the caching annotation.  `INFO` level because in practice we seem to have trouble with knowing whether and where the URL values are updating.
Yes.  This gating prevents computing a log message that won't be used.  If it the log message merely an object that would be `toString()` ed, then a log message template using a `{}` placeholder would be sufficient without a gated `logger.info`, 

    logger.info("{}", logMessageObject);

but because the content of the log call is an actual method invocation, the placeholder approach wouldn't prevent the computation.

It would be easy to argue that the `if (logger.isInfoEnabled()) {" isn't worth the noise in the source code, since in practice this code will probably not be run with logging at a level less verbose than `INFO` and so the log message will in practice always be computed anyway.  It's idiomatic boilerplate noise, though, and the method still feels readable with it.