Replace Java 15 with Java 16 in Travis CI.
diff --git a/.travis.yml b/.travis.yml
index b3d70b8..ad4d049 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -22,7 +22,7 @@
 jdk:

   - openjdk8

   - openjdk11

-  - openjdk15

+  - openjdk16

   - openjdk-ea

 

 matrix: