[gh-1] Adding dn efficiency graph and Site exit code.
These commits add the 2 graphs mentioned in: https://jira.opensciencegrid.org/browse/GRATIAWEB-19 https://jira.opensciencegrid.org/browse/GRATIAWEB-20
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These commits add the 2 graphs mentioned in: https://jira.opensciencegrid.org/browse/GRATIAWEB-19 https://jira.opensciencegrid.org/browse/GRATIAWEB-20