Add Google's algorithm

[filipeglfw]

@mbitson I have found a repo with Google's official tool reverse engineered. Forked it and extended to generate the A100-A700 colors.

I've been trying to incorporate in your tool, but am not very familiar with AngularJS

If someone wants to helm migrating, the code is here: https://github.com/filipeglfw/material-palette-generator/blob/master/src/index.js

[martinsotirov]

This would be very helpful, as this tool generates dark shades that are too similar and not dark enough compared to Google's palettes.