Update PromisesSwift deployment targets to match PromisesObjc.

I'm getting this error while attempting to push PromisesSwift to trunk:
"Specs satisfying the `PromisesObjC (= 2.3.0)` dependency were found, but they required a higher minimum deployment target.) during validation."

PromisesSwift.podspec

@@ -13,7 +13,7 @@ Pod::Spec.new do |s|
                      DESC
 
   s.ios.deployment_target  = '9.0'
-  s.osx.deployment_target  = '10.10'
+  s.osx.deployment_target  = '10.11'
   s.tvos.deployment_target = '9.0'
   s.watchos.deployment_target = '2.0'
   s.swift_versions = ['5.0', '5.2']