Bump to v3.0.0.

internal/MapCache.js

@@ -0,0 +1,24 @@
+import mapDelete from './mapDelete';
+import mapGet from './mapGet';
+import mapHas from './mapHas';
+import mapSet from './mapSet';
+
+/**
+ * Creates a cache object to store key/value pairs.
+ *
+ * @private
+ * @static
+ * @name Cache
+ * @memberOf _.memoize
+ */
+function MapCache() {
+  this.__data__ = {};
+}
+
+// Add functions to the `Map` cache.
+MapCache.prototype['delete'] = mapDelete;
+MapCache.prototype.get = mapGet;
+MapCache.prototype.has = mapHas;
+MapCache.prototype.set = mapSet;
+
+export default MapCache;