Update podspec

Author: ra1028

Carbon.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |spec|
   spec.name = 'Carbon'
-  spec.version  = '0.2.0'
+  spec.version  = '0.3.0'
   spec.author = { 'ra1028' => 'r.fe51028.r@gmail.com' }
   spec.homepage = 'https://github.com/ra1028/Carbon'
   spec.documentation_url = 'https://ra1028.github.io/Carbon'
@@ -9,7 +9,7 @@ Pod::Spec.new do |spec|
   spec.source_files = 'Sources/**/*.swift'
   spec.license = { :type => 'Apache 2.0', :file => 'LICENSE' }
   spec.requires_arc = true
-  spec.swift_version = '4.2'
+  spec.swift_versions = ['4.2', '5.0']
   spec.ios.deployment_target = '10.0'
   spec.dependency 'DifferenceKit/Core', "~> 1.1"
   spec.ios.frameworks = 'UIKit'