Updating this repo to v3

[Dave Crossland]

@m4rc1e emailed me about this topic, I've taken the liberty of transforming his thoughtful email into this issue :)

• Transfer org

Move from https://github.com/google/roboto to https://github.com/googlefonts/roboto

• Commit History

I plan on overwriting github.com/google/Roboto with https://github.com/TypeNetwork/Roboto, tagging the last commit on the v2 lineage, then doing some fancy git commit rebasing to bring the history of the latter onto the former; this will nuke the v2 stuff but its all unmaintained so, see ya. 

• Unit Tests

For each unit test in google/Roboto:v2 I'd like to make a sheet and review and annotate it with @m4rc1e, @dberlow and @sannorozco to determine if it is still relevant, and ask @anthrotype and @rsheeter (and anyone else) to review.

Then for those tests which are worth keeping, port them into either the GF fontbakery profile, or a Roboto project profile.

• Build Script

While v2 uses a Makefile, I don't feel tied to that.

That Makefile has a few targets, so I'd like the follow the same review process as above.

I welcome others ideas about what should be done to make the upcoming v3 era of this repo as good as the v2 one :)

[Dave Crossland]

Org transfer complete