post_install do |installer|
  installer.pods_project.targets.each do |target|
    target.build_configurations.each do |config|
      config.build_settings['SWIFT_VERSION'] = '4.1'
    end
  end

  swift33Targets = ['', '']
  installer.pods_project.targets.each do |target|
      if oldSwiftTargets.include? target.name
          target.build_configurations.each do |config|
              config.build_settings['SWIFT_VERSION'] = '3.3'
          end
      end
  end

end