Skip test_cards_view_with_three_apps.py due to it failing intermittently on device.
http://qa-selenium.mv.mozilla.com:8080/job/b2g.hamachi.mozilla-b2g28_v1.3.adhoc/6/Skip
Merge pull request #16172 from chirarobert/v1.3_skip_cards_view_test

Skip test_cards_view_with_three_apps.py due to it failing intermittently...
Merge branch 'v1.3' into v1.3t