I am using the Xcode 8.0 GM. I created a default single-view app with my deployment target set to 9.0.
In my Podfile I\'m targeting the bleeding edge Swift 3 branch:
Update the pod to 1.1.0.rc using the below command.
sudo gem install cocoapods
use the blow snippet at the end.
post_install do |installer|
    installer.pods_project.targets.each do |target|
        target.build_configurations.each do |config|
            config.build_settings['SWIFT_VERSION'] = '3.0'
        end
    end
end
this helps.