no issue
- drop phantomjs tests both locally and on Travis
- instruct Travis to install latest Chrome and Firefox
- start an X server when running the client tests on Travis
- update testem config to start Chrome and Firefox in both local and CI tests
- fix testing preview sizing in Firefox as it doesn't support `zoom: 50%` style
- improve infinite scroll testing to be more reliable
- fix post acceptance test to handle both mobile and desktop views
closes#6385
- redirect to 404 when post is not found
- replace replaceRoute calls with replaceWith calls in routes (replaceRoute is only available on controllers)
- add post mirage factory
- add acceptance test for post 404 redirection
