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.