Update deployment target in podspec file

KeychainAccess.podspec

@@ -28,7 +28,7 @@ Pod::Spec.new do |s|
 
   s.swift_version = '5.1'
 
-  s.ios.deployment_target = '8.0'
+  s.ios.deployment_target = '9.0'
   s.osx.deployment_target = '10.9'
   s.watchos.deployment_target = '3.0'
   s.tvos.deployment_target = '9.0'