Graph preview images

Write graphs one at a time.  I was seeing a race condition where I would
get back the same plot.ly graph ID if I submitted two separate graphs at
the same time.

Create a preview image using the `plotly.getFigure` and
`plotly.saveImage` APIs and save it into an Azure blob for web access by
the viewer component.

Save the graph URL, preview image, and route name into
`travelTimeIDToPlotlyUrlTable` for easy display of graphs in the web
component.
Remove accidentally added image

Oops
Web front-end
Revert "Web front-end"

This reverts commit 5a14c02c616694971f4985225783c242568f7dd9.
Revert "Revert "Web front-end""

This reverts commit 9238ddaaace212976b693ec9b2102dc3be2384a7.
derp
Get rid of config.js so I don't leak my Azure creds again -.-