[refactor] change Segment to have Maybe Hex.Direction instead of Hex.Direction. Matches change to the Haskell implementation in 0b3600a8b7d4766e63f7ad0efb91d39e33727eeb
[refactor] change Segment to have Maybe Hex.Direction instead of Hex.Direction.
Matches change to the Haskell implementation in 0b3600a8b7d4766e63f7ad0efb91d39e33727eeb

danmane/abalone,danmane/abalone,danmane/abalone,danmane/abalone,danmane/abalone,danmane/abalone