Revert "python: docker: 2.7.0 -> 3.0.0"
Revert "python: docker: 2.7.0 -> 3.0.0"

`pythonPackages.docker` isn't compatible with `docker-compose` 1.18 and
causes severe breackage when running `docker-compose up --build`.

See https://github.com/docker/compose/issues/5685 for further reference.

This reverts commit 2a8a058a217f286e562a8c8cc5d112f9d614dfeb.

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