bump selenium webdriver version from 2.53.0 to 2.53.4
bump selenium webdriver version from 2.53.0 to 2.53.4

new version works with Firefox 47.0.1

Change-Id: I1166efff2fe36999d50933ec695d2ae7b1b1122f
Reviewed-on: https://gerrit.instructure.com/85457
Tested-by: Jenkins
Reviewed-by: Robert Lamb <bf934bf7cdbebe5899399a138c0cb75c4d783999@instructure.com>
Product-Review: Robert Lamb <bf934bf7cdbebe5899399a138c0cb75c4d783999@instructure.com>
QA-Review: Robert Lamb <bf934bf7cdbebe5899399a138c0cb75c4d783999@instructure.com>

HotChalk/canvas-lms,grahamb/canvas-lms,venturehive/canvas-lms,SwinburneOnline/canvas-lms,dgynn/canvas-lms,SwinburneOnline/canvas-lms,grahamb/canvas-lms,dgynn/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,SwinburneOnline/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,matematikk-mooc/canvas-lms,venturehive/canvas-lms,matematikk-mooc/canvas-lms,instructure/canvas-lms,fronteerio/canvas-lms,sfu/canvas-lms,HotChalk/canvas-lms,sfu/canvas-lms,HotChalk/canvas-lms,grahamb/canvas-lms,matematikk-mooc/canvas-lms,grahamb/canvas-lms,fronteerio/canvas-lms,djbender/canvas-lms,venturehive/canvas-lms,SwinburneOnline/canvas-lms,djbender/canvas-lms,fronteerio/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,fronteerio/canvas-lms,instructure/canvas-lms,dgynn/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,HotChalk/canvas-lms,instructure/canvas-lms,dgynn/canvas-lms,matematikk-mooc/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,djbender/canvas-lms