[Travis] Update configuration for new mac workers

.travis.yml

+
+# Sets Travis to run the Ruby specs on OS X machines which are required to
+# build the native extensions of Xcodeproj.
+#
 language: objective-c
+
 env:
-  # This is what 10.8.x comes with and we want to support that.
-  - RVM_RUBY_VERSION=system NOEXEC_DISABLE=1 XCODEPROJ_BUILD=1 BUNDLE_WITHOUT='debugging:documentation' RUBY_VERSION_SPECIFIC='sudo ln -s /usr/bin/llvm-gcc-4.2 /usr/bin/gcc-4.2' SSL_CERT_FILE=/usr/local/share/cacert.pem GIT_AUTHOR_NAME=CocoaPods GIT_AUTHOR_EMAIL=cocoapods@example.com PYTHONPATH=/usr/local/lib/python2.7/site-packages
-  - RVM_RUBY_VERSION=2.0.0-p247 NOEXEC_DISABLE=1 XCODEPROJ_BUILD=1 BUNDLE_WITHOUT='debugging:documentation' RUBY_VERSION_SPECIFIC='sudo gem install bundler --no-ri --no-rdoc' GIT_AUTHOR_NAME=CocoaPods GIT_AUTHOR_EMAIL=cocoapods@example.com PYTHONPATH=/usr/local/lib/python2.7/site-packages
+  - RVM_RUBY_VERSION=system
+  - RVM_RUBY_VERSION=1.8.7-p358
+
 before_install:
   - curl http://curl.haxx.se/ca/cacert.pem -o /usr/local/share/cacert.pem
-  # - sh -c 'if [ "$RVM_RUBY_VERSION" != "system" ]; then rvm install $RVM_RUBY_VERSION --without-tcl --without-tk; fi'
-  - source ~/.rvm/scripts/rvm && rvm use $RVM_RUBY_VERSION
-install: eval $RUBY_VERSION_SPECIFIC && rake bootstrap[use_bundle_dir]
-script: bundle exec rake spec:ci
+  - source ~/.rvm/scripts/rvm
+  - if [[ $RVM_RUBY_VERSION != 'system' ]]; then rvm install $RVM_RUBY_VERSION; fi
+  - rvm use $RVM_RUBY_VERSION
+  - if [[ $RVM_RUBY_VERSION == 'system' ]]; then export ARCHFLAGS=-Wno-error=unused-command-line-argument-hard-error-in-future; fi
+  - if [[ $RVM_RUBY_VERSION == 'system' ]]; then sudo gem install bundler --no-ri --no-rdoc; else gem install bundler --no-ri --no-rdoc; fi
+
+install:
+  - bundle install --without=debugging documentation --path ./travis_bundle_dir
+
+script: rake spec:ci
+
 notifications:
   campfire:
     on_success: change
     on_failure: always
     rooms:
       - secure: "qOE5zmgaHe/qQu3W9rmj7wygA5Ivl+cx50fqWGag2bdRl8ly5yj1NVoOKk/O\nZmQc4Lze+301uvTXi+r5v8A/tF6W1kUZw7yBiKuXoYFUGmDiVR9o2I/FPwkL\ngSzPJttrXTQfkQ4PbnrkX+JO+5bLWrKaO0hKXT4B2yUu4UXLVk0="
-