Update travis.yml for all repos to change
-osx_image: beta-xcode6.3
+osx_image: xcode6.4

aerogear-ios-push
aerogear-ios-oauth2
aerogear-ios-http
aerogear-ios-sync-client
aerogear-ios-sync
aerogear-ios-jsonsz
aerogear-diffmatchpatch-ios
aerogear-otp-ios
aerogear-crypto-ios