add 'openjdk11' to Travis build matrix
diff --git a/.travis.yml b/.travis.yml
index ad87625..3c67709 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -21,6 +21,7 @@
   - oraclejdk7

   - oraclejdk8

   - oraclejdk9

+  - openjdk11

 

 after_success:

   - mvn clean cobertura:cobertura coveralls:report