Updated openstack/openstack
Project: openstack/sahara  9d7067e627997fe7553e087d46d60a1d9ed3dfbd

Add Spark to overview and feature matrix

Add Spark to the existing documentation in the overview page and in the
feature matrix for plugins.
Also use the more general 'data intensive application' instead of Hadoop
when referring to the kind of applications Sahara is able to handle.

Change-Id: Ibebeeaada6defa2549026b39e8c6faa23aba9cb8