Adds 2.16 docs to the list of older docs
Adds 2.16 docs to the list of older docs

dkliban/pulpproject.org,pulp/pulpproject.org,dkliban/pulpproject.org,dkliban/pulpproject.org,bmbouter/pulpproject.org,bmbouter/pulpproject.org,bmbouter/pulpproject.org,pulp/pulpproject.org,pulp/pulpproject.org,bmbouter/pulpproject.org,dkliban/pulpproject.org,pulp/pulpproject.org