Update CI bits

.github/workflows/dart.yml

@@ -1,36 +1,36 @@
 name: Dart
 
 on:
+  # Run on PRs and pushes to the default branch.
   push:
     branches: [ master ]
   pull_request:
     branches: [ master ]
+  schedule:
+    - cron: "0 0 * * 0"
+
+env:
+  PUB_ENVIRONMENT: bot.github
+  DISPLAY: ':99'
 
 jobs:
   test:
     runs-on: ubuntu-latest
-
-    env:
-      DISPLAY: ':99'
-
+    strategy:
+      matrix:
+        sdk: [2.12.0, dev]
     steps:
       - uses: actions/checkout@v2
-      - uses: cedx/setup-dart@v2
+      - uses: dart-lang/setup-dart@v1.0
         with:
-          release-channel: stable
-          version: latest
-
-      - name: Print Dart SDK version
-        run: dart --version
+          sdk: ${{ matrix.sdk }}
 
-      - name: Install dependencies
-        run: dart pub get
+      - run: dart pub get
+        id: install
 
-      - name: Analyze project source
-        run: dart analyze
+      - run: dart analyze --fatal-infos
 
       - name: Run Xvfb 
         run: Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 &
 
-      - name: Run tests
-        run: dart test
+      - run: dart test