Fix rendering on firefox

Rendering on firefox was broken due to the difference in time when DOM
loads - without deferReadiness it was sometimes failing to add
ember-application element to body

assets/scripts/travis.coffee

@@ -64,6 +64,9 @@ window.Travis = TravisApplication.create(
   LOG_TRANSITIONS: true
 )
 
+unless window.testMode
+  Travis.deferReadiness()
+
 $.extend Travis,
   run: ->
     Travis.advanceReadiness() # bc, remove once merged to master