Check empty tag

[prabhuramachandran]

• Ignore empty tags.
• Also fix issues with integration tests and tornado 5.x This does need a rethink as I suspect the current approach is just a dirty hack. Works for now though.

[codecov-io]

Codecov Report

:exclamation: No coverage uploaded for pull request base (master@f89e5dc). Click here to learn what that means. The diff coverage is 88.88%.

@@            Coverage Diff            @@
##             master      #18   +/-   ##
=========================================
  Coverage          ?   88.43%           
=========================================
  Files             ?        9           
  Lines             ?     1556           
  Branches          ?      269           
=========================================
  Hits              ?     1376           
  Misses            ?      117           
  Partials          ?       63

Impacted Files	Coverage Δ
vixen/vixen_ui.py	69.81% <100%> (ø)
vixen/vixen.py	88.7% <85.71%> (ø)

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