issue-10 - fix javadoc code example

cadc-access-control/src/main/java/ca/nrc/cadc/ac/GroupURI.java

@@ -89,7 +89,9 @@ public class GroupURI
      * Attempts to create a URI using the specified uri. The is expected
      * to be in the format:
      *
+     * <code>
      * ivo://<authority>/gms?<groupName>
+     * </code>
      *
      * @param uri The URI to use.
      * @throws IllegalArgumentException if the URI scheme is not vos