Bump to v4.0.0.

internal/hashDelete.js

@@ -0,0 +1,15 @@
+import hashHas from './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];
+}
+
+export default hashDelete;