Bump to v4.0.0.

internal/hashDelete.js

@@ -0,0 +1,16 @@
+define(['./hashHas'], function(hashHas) {
+
+  /**
+   * Removes `key` and its value from the hash.
+   *
+   * @private
+   * @param {Object} hash The hash to modify.
+   * @param {string} key The key of the value to remove.
+   * @returns {boolean} Returns `true` if the entry was removed, else `false`.
+   */
+  function hashDelete(hash, key) {
+    return hashHas(hash, key) && delete hash[key];
+  }
+
+  return hashDelete;
+});