Microsoft-r install script should use Ambari libraries instead of direct shell calls

In the install script of the management-pack we do everything using shell calls. Instead we should use Ambari's python libraries.
Example:

shell.call('sudo -u hdfs hadoop fs -mkdir -p /share')

As reference you can use the scripts of HDFS: https://github.com/apache/ambari/tree/trunk/ambari-server/src/main/resources/common-services/HDFS/2.1.0.2.0/package/scripts which make good use of Ambari libraries. Microsoft-R scripts should use just like these.