New active fork of Grumpy, a Go-based python2 runtime

This project got a lot of attention when it was first released, but then the original repo went dark. Some community members have decided to take up the mantle and have issued a rallying cry. The new repo is https://github.com/grumpyhome/grumpy.

Some more discussion on the original repo: https://github.com/google/grumpy/issues/406#issuecomment-402...