Integrate Marc Foley's gfregression app into a new dashboard page

[felipesanches]

Originally submitted at fonttools/fontbakery#1123

@m4rc1e said:

"Hey Felipe and Dave,

I think we should merge my gfregression app into Font Bakery. Instead of having lots of seperate repos/apps/libraries, we should focus on consolidating them.

It also fits FB's brief nicely

Tools to prepare font families for inclusion in github.com/google/fonts

I use it for cross platform testing a collection of fonts vertical metrics, against the same fonts which are hosted on fonts.google.com.

Left: local fonts | Right: fonts.google.com

I also see we are pushing for a UI for FB. I've built this app with Flask and Jinja2, keeping everything as simple as possible. I would opt for AWS or Digiocean over App Engine, due to our dependencies.

Cheers,
Marc"

To which @davelab6 replied: "Agree, but I would like Felipe to focus on getting the checker working first and then build this comparison feature in.

Thus moving this to 0.4.0"