Use Xcode 11.2 instead

Author: jdnichollsc

.travis.yml

@@ -9,7 +9,7 @@ matrix:
       os: osx
       env:
         - WebPack="iOS"
-      osx_image: xcode10.2
+      osx_image: xcode11.2
       language: node_js 
       node_js: "10"
       jdk: oraclejdk8
@@ -32,8 +32,8 @@ matrix:
     - os: osx
       env: 
         - BuildiOS="12"
-        - Xcode="10.0"
-      osx_image: xcode10.2
+        - Xcode="11.2"
+      osx_image: xcode11.2
       language: node_js 
       node_js: "10"
       jdk: oraclejdk8
@@ -55,7 +55,7 @@ matrix:
       language: node_js
       node_js: "10"
       jdk: oraclejdk8
-      osx_image: xcode10.2
+      osx_image: xcode11.2
       script: cd src && npm run demo.ios
 
 android: