fixed runner tests

Author: DavertMik

lib/container.js

@@ -39,8 +39,14 @@ class Container {
    */
   static create(config, opts) {
     asyncHelperPromise = Promise.resolve();
-    this.createMocha(config, opts);
 
+    // dynamically create mocha instance
+    const mochaConfig = config.mocha || {};
+    if (config.grep && !opts.grep) mochaConfig.grep = config.grep;
+    this.createMocha = () => (container.mocha = MochaFactory.create(mochaConfig, opts || {}));
+    this.createMocha();
+
+    // create support objects
     container.support = {};
     container.helpers = createHelpers(config.helpers || {});
     container.translation = loadTranslation(config.translation || null, config.vocabularies || []);