Require Tornado 4.4+ for tests.
Require Tornado 4.4+ for tests.

Because of behaviour change related to d392f403e3a94a34fe64192c48b33f47cbf9bbeb

pimusicbox/mopidy-musicbox-webclient,woutervanwijk/Mopidy-MusicBox-Webclient,pimusicbox/mopidy-musicbox-webclient,woutervanwijk/Mopidy-MusicBox-Webclient,pimusicbox/mopidy-musicbox-webclient,woutervanwijk/Mopidy-MusicBox-Webclient