Keep track of memory consumed on the nodes, log that, and
generate an overall cluster value for 'pods-per-Gb'.
Generate this data here, whilst we have the data to hand, as
it can get much more difficult to calculate this information
the further you get down the monitoring stream (such as the
farther you get into an ELK stack).
Signed-off-by: Graham Whaley <graham.whaley@intel.com>