Bump the min deployment target on macOS to 10.11

This avoid the libarclite.a issue during linking

Author: dreampiggy

README.md

@@ -11,7 +11,7 @@ This also contains the Swift Package Manager support
 ## Requirements
 
 + iOS 8
-+ macOS 10.10
++ macOS 10.11
 + tvOS 9.0
 + watchOS 2.0
 

libwebp.podspec

@@ -10,7 +10,7 @@ Pod::Spec.new do |s|
   s.compiler_flags = '-D_THREAD_SAFE'
   s.requires_arc = false
 
-  s.osx.deployment_target = '10.10'
+  s.osx.deployment_target = '10.11'
   s.ios.deployment_target = '9.0'
   s.tvos.deployment_target = '9.0'
   s.watchos.deployment_target = '2.0'