Add back support for OS X 10.11 (#645)

Package.swift

@@ -29,7 +29,7 @@ let package = Package(
     name: "SnapKit",
     platforms: [
         .iOS(.v10),
-        .macOS(.v10_12),
+        .macOS(.v10_11),
         .tvOS(.v10)
     ],
     products: [

SnapKit.podspec

@@ -9,7 +9,7 @@ Pod::Spec.new do |s|
   s.source = { :git => 'https://github.com/SnapKit/SnapKit.git', :tag => '5.0.1' }
 
   s.ios.deployment_target = '10.0'
-  s.osx.deployment_target = '10.12'
+  s.osx.deployment_target = '10.11'
   s.tvos.deployment_target = '10.0'
 
   s.source_files = 'Source/*.swift'

SnapKit.xcodeproj/project.pbxproj

@@ -538,7 +538,7 @@
 				INFOPLIST_FILE = "$(SRCROOT)/Source/Info.plist";
 				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
-				MACOSX_DEPLOYMENT_TARGET = 10.12;
+				MACOSX_DEPLOYMENT_TARGET = 10.11;
 				PRODUCT_BUNDLE_IDENTIFIER = "io.snapkit.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_BUNDLE_PACKAGE_TYPE = FMWK;
 				PRODUCT_NAME = SnapKit;
@@ -561,7 +561,7 @@
 				INFOPLIST_FILE = "$(SRCROOT)/Source/Info.plist";
 				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
-				MACOSX_DEPLOYMENT_TARGET = 10.12;
+				MACOSX_DEPLOYMENT_TARGET = 10.11;
 				PRODUCT_BUNDLE_IDENTIFIER = "io.snapkit.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_BUNDLE_PACKAGE_TYPE = FMWK;
 				PRODUCT_NAME = SnapKit;
@@ -580,7 +580,7 @@
 				INFOPLIST_FILE = "$(SRCROOT)/Tests/SnapKitTests/Info.plist";
 				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks @loader_path/../Frameworks @executable_path/../Frameworks";
-				MACOSX_DEPLOYMENT_TARGET = 10.12;
+				MACOSX_DEPLOYMENT_TARGET = 10.11;
 				PRODUCT_BUNDLE_IDENTIFIER = "io.snapkit.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_VERSION = 4.2;
@@ -595,7 +595,7 @@
 				INFOPLIST_FILE = "$(SRCROOT)/Tests/SnapKitTests/Info.plist";
 				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks @loader_path/../Frameworks @executable_path/../Frameworks";
-				MACOSX_DEPLOYMENT_TARGET = 10.12;
+				MACOSX_DEPLOYMENT_TARGET = 10.11;
 				PRODUCT_BUNDLE_IDENTIFIER = "io.snapkit.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";