Add JDK 17 build in CI

Author: fwcd

.github/workflows/build.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: ['11']
+        java: ['11', '17']
     steps:
       - uses: actions/checkout@v2
       - name: Setup JDK