Remove Travis osx java testing

Removed until doxygen testing is ported to something that doesn't use
com.sun.javadoc which was remoed in jdk 13

.travis.yml

@@ -449,6 +449,11 @@ matrix:
       env: SWIGLANG=php VER=7.2
       sudo: required
       dist: xenial
+    # jdk 13 has removed tools.jar resulting in: CommentParser.java:2: error: package com.sun.javadoc does not exist
+    - compiler: clang
+      os: osx
+      env: SWIGLANG=java CPP17=1
+      osx_image: xcode10.2
     # Sometimes hits the Travis 50 minute time limit
     - compiler: clang
       os: osx