Follow up fix to bug https://bugs.activestate.com/show_bug.cgi?id=103199

Do a 'bundle update' to update Gemfile.lock before doing 'bundle install'.
Elasticsearch: add instructions to get ES working on a cluster.

Bugzilla: https://bugs.activestate.com/show_bug.cgi?id=102689
JIRA: https://activestate.atlassian.net/browse/STO-355