Remove xfail and update test_that_checks_apps_are_sorted_by_date
Bug https://bugzilla.mozilla.org/show_bug.cgi?id=753287 has been marked as
RESOLVED WONTFIX, so I removed the xfail.
Merge pull request #205 from teodosia/remove-xfail-sort-dev-hub

Remove xfail and update test_that_checks_apps_are_sorted_by_date