build on jdk 11

Author: vertical-blank

.github/workflows/maven.yml

@@ -16,10 +16,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Set up JDK 1.8
+    - name: Set up JDK 11
       uses: actions/setup-java@v1
       with:
-        java-version: 1.8
+        java-version: 11
     - name: Build with Maven
       run: mvn -e -B package --file pom.xml
     - name: Codecov