iOS warning: The iOS deployment

将下述内容添加在PodFile内容里的最下方，重新执行Pod install

post_install do |installer|
    installer.pods_project.targets.each do |target|
        target.build_configurations.each do |config|
            config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '9.0'
        end
    end
end

NOTE:注意 ['IPHONEOS_DEPLOYMENT_TARGET'] = '9.0' 中的版本号要与你的 platform :ios, '9.0' 一致