watson: 1.8.0 -> 1.9.0
watson: 1.8.0 -> 1.9.0

The src was switched to GitHub because PyPi does not contain all the
necessary test artefacts. Furthermore, a custom patch to support the
latest arrow version was added.

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs