Update main.yml

.github/workflows/main.yml

@@ -15,13 +15,18 @@ jobs:
   # This workflow contains a single job called "build"
   build:
     # The type of runner that the job will run on
-    runs-on:
-      - image: cirrusci/flutter:beta
+    runs-on: ubuntu-latest
 
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps:
     # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
     - uses: actions/checkout@v2
+    - uses: actions/setup-java@v1
+      with:
+        java-version: '12.x'
+    - uses: subosito/flutter-action@v1
+      with:
+        flutter-version: '1.18.0-11.1.pre'
 
     # Runs a single command using the runners shell
     - name: Run flutter doctor