update travis for jdk 11 and 8

Author: shroffk

.travis.yml

@@ -1,19 +1,13 @@
 sudo: required
 language: java
-jdk:
-  - oraclejdk8
-  - oraclejdk9
 
 matrix:
   include:
     - jdk: openjdk8
       before_install:
         - export MVN_OPT='--projects "!gpclient/gpclient-javafx"'
-    - jdk: openjdk10
-      before_install:
-        - rm "${JAVA_HOME}/lib/security/cacerts"
-        - ln -s /etc/ssl/certs/java/cacerts "${JAVA_HOME}/lib/security/cacerts"
-        - export MVN_OPT='--projects "!gpclient/gpclient-javafx"'
+    - jdk: openjdk11
+
 env:
   - EPICS_PVA_ADDR_LIST=127.255.255.255