Added mapping to/from Map.

Author: wessberg

README.md

@@ -49,13 +49,17 @@ The marshalled version of the input data.
 * [X] Casting from/to `undefined`.
 * [ ] Casting from/to `Date`.
 * [X] Casting from/to `Function`
-* [ ] Casting from/to `Map`
+* [X] Casting from/to `Map`
 * [ ] Casting from/to `WeakSet`
 * [ ] Casting from/to `WeakMap`
 * [ ] Casting from/to `RegExp`
 
 ## Changelog:
 
+**v1.0.22**:
+
+- Added mapping to/from `Map`.
+
 **v1.0.21**:
 
 - Made sure that quoted strings will not be re-quoted.