use JDK 17 (ref #329)

Author: jvmlet

.github/workflows/gradle.yml

@@ -20,7 +20,7 @@ jobs:
       uses: actions/setup-java@v2
       with:
         distribution: 'zulu'
-        java-version: "11"
+        java-version: "17"
     - name: Grant execute permission for gradlew
       run: chmod +x gradlew
     - name: Build with Gradle

.travis.yml

@@ -1,6 +1,6 @@
 language: java
 jdk:
-  - oraclejdk17
+  - openjdk17
 #sudo: false
 dist: trusty
 before_cache: