Run GitHub actions integration tests with Java 16 (#456)

diff --git a/.github/workflows/maven.yml b/.github/workflows/maven.yml
index afa260b..45f3655 100644
--- a/.github/workflows/maven.yml
+++ b/.github/workflows/maven.yml
@@ -67,7 +67,7 @@
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macOS-latest]
-        java: [8, 11, 15, 16-ea]
+        java: [8, 11, 16]
       fail-fast: false
     runs-on: ${{ matrix.os }}