Run spotlessCheck only in JDK 11 on GitHub Actions

Author: emlun

.github/workflows/code-formatting.yml

@@ -0,0 +1,25 @@
+# This name is shown in the status badge in the README
+name: code-formatting
+
+on: [push, pull_request]
+
+jobs:
+  test:
+    name: JDK ${{matrix.java}}
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        java: [11]
+
+    steps:
+    - name: Check out code
+      uses: actions/checkout@v1
+
+    - name: Set up JDK
+      uses: actions/setup-java@v1
+      with:
+        java-version: ${{ matrix.java }}
+
+    - name: Check code formatting
+      run: ./gradlew spotlessCheck

build.gradle

@@ -111,7 +111,6 @@ subprojects {
       scalafmt('2.6.3').configFile(rootProject.file('scalafmt.conf'))
     }
   }
-  tasks.check.dependsOn spotlessCheck
 }
 
 allprojects {