Update .travis.yml

fix jdk versions

Author: srl295

.travis.yml

@@ -9,8 +9,10 @@ language: java
 sudo: required
 
 jdk:
-  - openjdk7
-  - oraclejdk8
+  - openjdk8
+  - openjdk9
+  - openjdk10
+  - openjdk11
 
 before_install:
   - echo -n | openssl s_client -connect scan.coverity.com:443 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' | sudo tee -a /etc/ssl/certs/ca-