Updated site's dependencies.
Updated site's dependencies.

This bumps e.g., `nokogiri` to a version not affected by CVE-2019-5477
anymore (not that it would have any impact on our use of it).

Review: https://reviews.apache.org/r/71367/

Gilbert88/mesos,kaysoky/mesos,Gilbert88/mesos,kaysoky/mesos,abudnik/mesos,dforsyth/mesos,Gilbert88/mesos,abudnik/mesos,dforsyth/mesos,Gilbert88/mesos,kaysoky/mesos,reneploetz/mesos,dforsyth/mesos,dforsyth/mesos,reneploetz/mesos,abudnik/mesos,dforsyth/mesos,kaysoky/mesos,dforsyth/mesos,Gilbert88/mesos,reneploetz/mesos,abudnik/mesos,dforsyth/mesos,Gilbert88/mesos,reneploetz/mesos,kaysoky/mesos,reneploetz/mesos,abudnik/mesos,Gilbert88/mesos,reneploetz/mesos,abudnik/mesos,reneploetz/mesos,abudnik/mesos,kaysoky/mesos,kaysoky/mesos