Reverting previous changes made to remove default-jre-headless from the
required mesos packages.  This will revert back to including this
package and not breaking the LD_LIBRARY_PATH which was not set when
using oracle jdk's.  Also added a test suite which covers oracle jdk 7
scenario's.
Added jre package check
Merge pull request #30 from mdsol/feature/refactor-serverspec-plus-oracle-jdk

Reverting previous changes made to remove default-jre-headless from the