[INFINITY-2884] Fix timing bug in certificate change test (#2017)
[INFINITY-2884] Fix timing bug in certificate change test (#2017)

* Fix timing bug in certificate change test

* Remove duplicate waiting for deploy plan to complete

vishnu2kmohan/dcos-commons,vishnu2kmohan/dcos-commons,vishnu2kmohan/dcos-commons,vishnu2kmohan/dcos-commons,mesosphere/dcos-commons,vishnu2kmohan/dcos-commons,mesosphere/dcos-commons,mesosphere/dcos-commons,mesosphere/dcos-commons,mesosphere/dcos-commons