pom update to fail fast when missing env variables

Added a plugin that validates all the ENV variables required for the new build.  
Otherwise test fail catastrophically (100s of failures), without a clear reason until you dig deeper.

<requireProperty><property>HCFS_CLASSNAME</property></requireProperty>
<requireProperty><property>HCFS_FILE_SYSTEM_CONNECTOR</property></requireProperty>
<requireProperty><property>GLUSTER_MOUNT</property></requireProperty>

FYI Also redid the formatting.