Include watchOS 4.0 in @available check (#579)

Author: aydegee

Sources/SnapshotTesting/Snapshotting/Any.swift

@@ -7,7 +7,7 @@ extension Snapshotting where Format == String {
   }
 }
 
-@available(macOS 10.13, *)
+@available(macOS 10.13, watchOS 4.0, *)
 extension Snapshotting where Format == String {
   /// A snapshot strategy for comparing any structure based on their JSON representation.
   public static var json: Snapshotting {

Sources/SnapshotTesting/Snapshotting/Codable.swift

@@ -2,7 +2,7 @@ import Foundation
 
 extension Snapshotting where Value: Encodable, Format == String {
   /// A snapshot strategy for comparing encodable structures based on their JSON representation.
-  @available(iOS 11.0, macOS 10.13, tvOS 11.0, *)
+  @available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, *)
   public static var json: Snapshotting {
     let encoder = JSONEncoder()
     encoder.outputFormatting = [.prettyPrinted, .sortedKeys]

Sources/SnapshotTesting/Snapshotting/URLRequest.swift

@@ -20,7 +20,7 @@ extension Snapshotting where Value == URLRequest, Format == String {
 
       let body: [String]
       do {
-        if pretty, #available(iOS 11.0, macOS 10.13, tvOS 11.0, *) {
+        if pretty, #available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, *) {
           body = try request.httpBody
             .map { try JSONSerialization.jsonObject(with: $0, options: []) }
             .map { try JSONSerialization.data(withJSONObject: $0, options: [.prettyPrinted, .sortedKeys]) }