Chart Tango results

Build the capability for a user to take
tango results + chart config files + transformation code from tango result format to a specific charting format

And display a nivo chart of the tango results. [varnish nivo](https://varnish.allenai.org/components/nivo)
This is a hard task if we want to support many many charting options and formats, and a trivial task to support a single non configurable chart. So what we do really depends on need and time.