spec: improve assignment publish spec

Change-Id: I35051d6a5460a40c53f5145f3c82fb32a0454af2
Reviewed-on: https://gerrit.instructure.com/87862
Tested-by: Jenkins
Reviewed-by: August Thornton <august@instructure.com>
Product-Review: Gentry Beckmann <gbeckmann@instructure.com>
QA-Review: Gentry Beckmann <gbeckmann@instructure.com>

Author: beckesea

spec/selenium/assignments/assignments_spec.rb

@@ -498,6 +498,7 @@ def create_assignment(publish = true, params = {name: "Test Assignment"})
         expect(f("#assignment-speedgrader-link")).to have_class("hidden")
 
         f("#assignment_publish_button").click
+        wait_for_ajaximations
 
         expect(@assignment.reload).to be_published
         expect(f("#assignment_publish_button")).to include_text("Published")