update deployment targets to make cocoapods build

KeychainSwift.podspec

@@ -17,7 +17,7 @@ Pod::Spec.new do |s|
   s.source_files = "Sources/*.swift"
   s.ios.deployment_target = "12.0"
   s.osx.deployment_target = "10.13"
-  s.watchos.deployment_target = "3.0"
+  s.watchos.deployment_target = "4.0"
   s.tvos.deployment_target = "12.0"
   s.swift_version = "5.0"
 end

KeychainSwift.xcodeproj/project.pbxproj

@@ -932,7 +932,7 @@
 				SWIFT_SWIFT3_OBJC_INFERENCE = Off;
 				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = 4;
-				WATCHOS_DEPLOYMENT_TARGET = 2.0;
+				WATCHOS_DEPLOYMENT_TARGET = 4.0;
 			};
 			name = Debug;
 		};
@@ -956,7 +956,7 @@
 				SWIFT_SWIFT3_OBJC_INFERENCE = Off;
 				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = 4;
-				WATCHOS_DEPLOYMENT_TARGET = 2.0;
+				WATCHOS_DEPLOYMENT_TARGET = 4.0;
 			};
 			name = Release;
 		};