Added Andrea Lanfranchi as an author (#2509)
Permission from the author granted by IfDefElse below.
[February 4, 2020 12:08 AM](https://gitter.im/ethereum-cat-herders/ProgPoW-review?at=5e3926873aca1e4c5f61e3ef)
Co-authored-by: Alex Beregszaszi <alex@rtfs.hu>
GitHub Diff