Merge pull request #74 from bradhowes/master

Fix compile errors in Xcode 8.3 beta

Source/Shared/Cache.swift

@@ -29,17 +29,28 @@ public final class Cache<T: Cachable>: HybridCache {
    - Parameter expiry: Expiration date for the cached object
    - Parameter completion: Completion closure to be called when the task is done
    */
+#if swift(>=3.1)
+  public override func add<T: Cachable>(_ key: String, object: T, expiry: Expiry? = nil, completion: (() -> Void)? = nil) {
+    super.add(key, object: object, expiry: expiry, completion: completion)
+  }
+#else
   public override func add(_ key: String, object: T, expiry: Expiry? = nil, completion: (() -> Void)? = nil) {
     super.add(key, object: object, expiry: expiry, completion: completion)
   }
-
+#endif
   /**
    Tries to retrieve the object from to the front and back cache storages.
 
    - Parameter key: Unique key to identify the object in the cache
    - Parameter completion: Completion closure returns object or nil
    */
+#if swift(>=3.1)
+  public override func object<T: Cachable>(_ key: String, completion: @escaping (_ object: T?) -> Void) {
+    super.object(key, completion: completion)
+  }
+#else
   public override func object(_ key: String, completion: @escaping (_ object: T?) -> Void) {
     super.object(key, completion: completion)
   }
+#endif
 }