Cocoapods Swift version setup for specific Pod

Podfile

#insert after all pods declaring (just put at the bottom of a file)
post_install do |installer|
    installer.pods_project.targets.each do |target|
        if target.name == 'POD_NAME_HERE'
            target.build_configurations.each do |config|
                config.build_settings['SWIFT_VERSION'] = '4.0'
            end
        end
    end
end