Update min target versions

SnapKit.podspec

@@ -8,8 +8,8 @@ Pod::Spec.new do |s|
   s.social_media_url = 'http://twitter.com/robertjpayne'
   s.source = { :git => 'https://github.com/SnapKit/SnapKit.git', :tag => '5.0.0' }
 
-  s.ios.deployment_target = '8.0'
-  s.osx.deployment_target = '10.11'
+  s.ios.deployment_target = '9.0'
+  s.osx.deployment_target = '10.12'
   s.tvos.deployment_target = '9.0'
 
   s.source_files = 'Source/*.swift'