Clean up the POM file and use public UserRegistry API to retrieve realms. 

Currently the POM file is relying on the jar file I downloaded from Liberty build. 

The correct way is below.  (Thanks to Scott Kurz, Jared Anderson, Kevin Grigorenko) 
<dependency>
      <groupId>com.ibm.websphere.appserver.api</groupId>
      <artifactId>com.ibm.websphere.appserver.api.basics</artifactId>
      <version>1.4.102</version>