UPDATE: podspec swift version

Author: Jinwook-Jeon

NXDrawKit.podspec

@@ -20,7 +20,6 @@ Pod::Spec.new do |s|
   s.social_media_url = 'https://twitter.com/nicejinux'
 
   s.ios.deployment_target = '8.0'
-  s.swift_version = '5.0'
   s.source_files = 'NXDrawKit/Classes/*'
   s.resource_bundles = {
     'NXDrawKit' => ['NXDrawKit/Assets/*']