Merge pull request #29 from thake/renovate/actions-checkout-3.x

Update actions/checkout action to v3

Author: thake

.github/workflows/gradle.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Set up JDK 1.8
       uses: actions/setup-java@v1
       with: