Parallel CI jobs (#201)

- flutter analyze
- flutter build linux
- flutter format
- flutter pub publish --dry-run
- flutter test

.github/workflows/flutter-ci.yml

@@ -9,33 +9,78 @@ on:
       - main
 
 jobs:
-  build:
+  analyze:
     runs-on: ubuntu-20.04
     steps:
-    
-    - uses: actions/checkout@v1
-    - uses: subosito/flutter-action@v1
+
+    - uses: actions/checkout@v2
+    - uses: subosito/flutter-action@v2
       with:
         channel: 'stable'
 
-    - name: Enable Linux desktop support
-      run: flutter config --enable-linux-desktop
-
     - name: Get dependencies
       run: flutter pub get
-
-    - name: Run tests
-      run: flutter test
 
-    - name: Check for any formatting issues
-      run: flutter format --set-exit-if-changed .
-
     - name: Check for any analyzer issues
       run: flutter analyze .
 
+  build:
+    runs-on: ubuntu-20.04
+    steps:
+
+    - uses: actions/checkout@v2
+    - uses: subosito/flutter-action@v2
+      with:
+        channel: 'stable'
+
+    - name: Get dependencies
+      run: flutter pub get
+
     - name: Install dependencies
       run: sudo apt install clang cmake curl ninja-build libgtk-3-dev pkg-config unzip
 
     - name: Build example
       run: flutter build linux -v
       working-directory: example/
+
+  format:
+    runs-on: ubuntu-20.04
+    steps:
+
+    - uses: actions/checkout@v2
+    - uses: subosito/flutter-action@v2
+      with:
+        channel: 'stable'
+
+    - name: Check for any formatting issues
+      run: flutter format --set-exit-if-changed .
+
+  pub:
+    runs-on: ubuntu-20.04
+    steps:
+
+    - uses: actions/checkout@v2
+    - uses: subosito/flutter-action@v2
+      with:
+        channel: 'stable'
+
+    - name: Get dependencies
+      run: flutter pub get
+
+    - name: Validate but do not publish the package
+      run: flutter pub publish --dry-run
+
+  test:
+    runs-on: ubuntu-20.04
+    steps:
+
+    - uses: actions/checkout@v2
+    - uses: subosito/flutter-action@v2
+      with:
+        channel: 'stable'
+
+    - name: Get dependencies
+      run: flutter pub get
+
+    - name: Run tests
+      run: flutter test