Add comprehensive tests for role middleware and fix package dependencies

node_modules/mocha/lib/nodejs/file-unloader.js

@@ -0,0 +1,15 @@
+'use strict';
+
+/**
+ * This module should not be in the browser bundle, so it's here.
+ * @private
+ * @module
+ */
+
+/**
+ * Deletes a file from the `require` cache.
+ * @param {string} file - File
+ */
+exports.unloadFile = file => {
+  delete require.cache[require.resolve(file)];
+};