Update podspec

Author: muukii

StackScrollView.podspec

@@ -8,7 +8,7 @@ Pod::Spec.new do |s|
   s.source           = { :git => 'https://github.com/muukii/StackScrollView.git', :tag => s.version.to_s }
   s.social_media_url = 'https://twitter.com/muukii0803'
 
-  s.ios.deployment_target = '8.0'
+  s.ios.deployment_target = '9.0'
   s.source_files = 'StackScrollView/**/*'
 
 end