avoid jdk12 for now unti spotbugs is jdk12 ready

Author: karussell

.travis.yml

@@ -12,8 +12,9 @@ env:
 matrix:
   include:
     - jdk: openjdk8
-    - env: JDK='OpenJDK 12'
-      install: . ./install-jdk.sh -F 12 -C
+    # spotbugs is not jdk 12 ready yet
+#    - env: JDK='OpenJDK 12'
+#      install: . ./install-jdk.sh -F 12 -C
     - env: JDK='OpenJDK 11'
       install: . ./install-jdk.sh -F 11 -C