Use java 17

Author: simonpoole

.github/workflows/javalib.yml

@@ -21,10 +21,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v1
-    - name: set up JDK 11
+    - name: set up JDK 17
       uses: actions/setup-java@v1
       with:
-        java-version: 11
+        java-version: 17
     - name: Dummy gradle.properties
       shell: bash
       run: |