Add unit test to check if class can be used

Author: EmmanuelDemey

test/factory-name.js

@@ -24,6 +24,10 @@ var invalid = [];
 valid.push({
     code: 'app.factory("eslintFactory", function() {});',
     options: ['eslint']
+}, {
+    code: 'app.factory("eslintFactory", EslintFactory); class EslintFactory {}',
+    options: ['eslint'],
+    parserOptions: {ecmaVersion: 6}
 }, {
     code: 'app.factory("eslintFactory", function() {});',
     options: [/^eslint/]