v0.5.0

• Added support for custom private middleware to be inserted into the Express server. This can be used to host a custom status endpoint for powering the status banner.
• Fixed security issue with acorn
• Added support for showing a system status banner powered by an optional endpoint to provide a status payload.
• Updated flyteidl and added support for additional Task execution phases
• Added code coverage support through codecov.io
• Minor layout updates to execution tables, and no showing queued time (if available) for Task Executions.