update test configuration to xcode8.3

Author: janpio

.travis.yml

@@ -28,17 +28,16 @@ matrix:
     os: linux
     language: node_js
     node_js: '4.2'
+  - env: PLATFORM=ios-9.3
+    os: osx
+    osx_image: xcode8.3
+    language: node_js
+    node_js: '4.2'
   - env: PLATFORM=ios-10.0
     os: osx
     osx_image: xcode8.3
     language: node_js
     node_js: '4.2'
-  # TBD SKIP for now:
-  # - env: PLATFORM=ios-10.0
-  #   os: osx
-  #   osx_image: xcode7.3
-  #   language: node_js
-  #   node_js: '4.2'
   # FUTURE TBD:
   # - env: PLATFORM=ios-11.4
   #   ...