Update drone to use nix

.drone.yml

@@ -1,34 +1,23 @@
 kind: pipeline
 name: default
+type: exec
 
 steps:
   - name: submodules
-    image: docker:git
     commands:
       - git submodule init
       - git submodule update --recursive --remote
 
-  - name: libreoffice
-    image: jess/libreoffice
+  - name: build
     commands:
-      - apk add --no-cache make
-      - ./compile.sh libreoffice
+      - nix-build
 
-  - name: revealjs
-    image: python:3-alpine
-    commands:
-      - apk add --no-cache make
-      - pip install pipenv
-      - pipenv install --system
-      - ./compile.sh revealjs
-
-  - name: publish
-    image: r.sbruder.de/drone-netlify
-    settings:
-      auth_token:
+  - name: push
+    environment:
+      NETLIFY_AUTH_TOKEN:
         from_secret: netlify_auth_token
-      dir: .
-      prod: 1
-    when:
-      branch:
-        - master
+    commands:
+      - nix-shell -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/24c9b05ac53e422f1af81a156f1fd58499eb27fb.tar.gz -p netlify-cli --run "netlify deploy --prod -d $(readlink -f result)"
+
+node:
+  nix: 1