chore(github action workflow): define branch for checkout to make sure intermediate commits are included

without defining branch, the second checkout would skip previous automatic commits
see actions/checkout#439

Author: Valentin Deyringer

.github/workflows/github-actions.yml

@@ -48,6 +48,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
+        with:
+          ref: ${{ github.ref_name }}
       - uses: actions/setup-java@v1
         with:
           java-version: 11
@@ -88,6 +90,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
+        with:
+          ref: ${{ github.ref_name }}
       - uses: actions/setup-java@v1
         with:
           java-version: 11