Update Java version of GitHub actions workflow to Java 14.

.github/workflows/maven.yml

@@ -18,7 +18,7 @@ jobs:
     - name: Set up JDK
       uses: actions/setup-java@v2
       with:
-        java-version: 11
+        java-version: 14
         distribution: 'zulu'
         
     - name: Run Maven Install