Upgrade bootstrap to v3.1

Change-Id: I679f068a7c75b6a63f6bf3649baa8837b13c24d7
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/2195
Tested-by: jenkins
Reviewed-by: Henry Robinson <henry@cloudera.com>
(cherry picked from commit 1be28cb0086320bc0505ffc09231a672c66f0e90)
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3647