Mark iOS tests as able to fail.

Travis updated their images to include an xctool that can randomly kill
tests, so mark them as flaky to avoid turning things red.

.travis.yml

@@ -71,5 +71,14 @@ matrix:
     # we moved to an OS X image that is 10.11.
     - os: osx
       env: CONFIG=python_cpp
+    # xctool 0.2.8 seems to have a bug where it randomly kills tests saying
+    # they failed.
+    #   https://github.com/facebook/xctool/issues/619
+    #   https://github.com/google/protobuf/issues/1232
+    # travis updated their images to include 0.2.8:
+    #   https://blog.travis-ci.com/2016-03-23-xcode-image-updates
+    # Mark the iOS test as flakey so these failures don't turn things red.
+    - os: osx
+      env: CONFIG=objectivec_ios
 notifications:
   email: false

travis.sh

@@ -171,13 +171,7 @@ internal_objectivec_common () {
   #  http://docs.travis-ci.com/user/osx-ci-environment/
   # We don't use a before_install because we test multiple OSes.
   brew update
-  # xctool 0.2.8 seems to have a bug where it randomly kills tests saying
-  # they failed. Disabling the updates, but letting it report about being
-  # updates as a hint that this needs to eventually get re-enabled.
-  #   https://github.com/facebook/xctool/issues/619
-  #   https://github.com/google/protobuf/issues/1232
-  brew outdated xctool || true
-  #brew outdated xctool || brew upgrade xctool
+  brew outdated xctool || brew upgrade xctool
   # Reused the build script that takes care of configuring and ensuring things
   # are up to date. Xcode and conformance tests will be directly invoked.
   objectivec/DevTools/full_mac_build.sh \