Update podspec

Author: shu223

Pulsator.podspec

@@ -1,14 +1,14 @@
 Pod::Spec.new do |s|
   s.name             = "Pulsator"
-  s.version          = "0.5.3"
+  s.version          = "0.6.0"
   s.summary          = "Pulse animation for iOS."
   s.homepage         = "https://github.com/shu223/Pulsator"
   s.screenshots      = "https://github.com/shu223/Pulsator/blob/master/demo.gif?raw=true"
   s.license          = 'MIT'
   s.author           = { "shu223" => "shuichi0526@gmail.com" }
   s.source           = { :git => "https://github.com/shu223/Pulsator.git", :tag => "#{s.version}" }
   s.social_media_url = 'https://twitter.com/shu223'
-  s.swift_version    = '4.2'
+  s.swift_version    = '5.0'
 
   s.ios.deployment_target = '8.0'
   s.osx.deployment_target = '10.9'