Add Java 17-EA to the GitHub build.
diff --git a/.github/workflows/maven.yml b/.github/workflows/maven.yml
index 80a8263..ab5b7fb 100644
--- a/.github/workflows/maven.yml
+++ b/.github/workflows/maven.yml
@@ -29,6 +29,8 @@
         include:
           - java: 16-ea
             experimental: true        
+          - java: 17-ea
+            experimental: true
         
     steps:
     - uses: actions/checkout@v2.3.4