Fix the driver and task configuartion to make the example work
Merge pull request #907 from yunseong/ys-fix-groupcomm-example

Fix the driver and task configuartion of Groupcomm example
Added -status to the HDI command line

This PR adds the -status flag to the HDI command line to query the cluster for the status of a given application
Merge pull request #908 from Microsoft-CISL/weimer_hdi_status

Added -status to the HDI command line. Self-merging as this can't possibly touch anything the tests on YARN and Local will cover.
Merge branch 'master' of https://github.com/Microsoft-CISL/REEF into MLSS