spec: test unpending

Change-Id: Iaf1414ea591d7f00c479972810151a52db73ec6a
Reviewed-on: https://gerrit.instructure.com/42721
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Shawn Meredith <shawn@instructure.com>
Product-Review: Shawn Meredith <shawn@instructure.com>
QA-Review: Shawn Meredith <shawn@instructure.com>

spec/models/course_spec.rb

@@ -1151,7 +1151,6 @@ describe Course, "gradebook_to_csv" do
     end
 
     it "should insert N/A for non-visible assignments" do
-      pending('fragile')
       csv = @course.gradebook_to_csv(:user => @teacher)
       csv.should_not be_nil
       rows = CSV.parse(csv)