add cachix to ci

.drone.yml

@@ -9,5 +9,10 @@ steps:
       - nix-channel --add https://nixos.org/channels/nixos-unstable nixos
       - nix-channel --add https://github.com/nix-community/home-manager/archive/master.tar.gz home-manager
       - nix-channel --update
-      - nix-build '<nixpkgs/nixos>' -j4 -A config.system.build.toplevel -I nixos-config=thinkpad/configuration.nix
+      - nix-env -iA cachix -f https://cachix.org/api/v1/install
+      - cachix use vijfhoek
+      - nix-build '<nixpkgs/nixos>' -j4 -A config.system.build.toplevel -I nixos-config=thinkpad/configuration.nix | cachix push vijfhoek
+    environment:
+      CACHIX_AUTH_TOKEN:
+        from_secret: CACHIX_AUTH_TOKEN