Jira ticket #MB-8240.  Turn off verbose logging for the install_libraries.rb script (this was the original state of the script before I edited it)

Change-Id: I52fa3c707bc54f0604b80b86ada249d8adf52d60
Reviewed-on: http://review.couchbase.org/26376
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>