Add qunit test and fix the rspec method

plugins/discourse-local-dates/test/javascripts/acceptance/local-dates-test.js.es6

@@ -0,0 +1,25 @@
+import { acceptance } from "helpers/qunit-helpers";
+import { clearPopupMenuOptionsCallback } from "discourse/controllers/composer";
+
+acceptance("Local Dates", {
+  loggedIn: true,
+  settings: { discourse_local_dates_enabled: true },
+  beforeEach() {
+    clearPopupMenuOptionsCallback();
+  }
+});
+
+test("local dates bbcode", async assert => {
+  await visit("/");
+  await click("#create-topic");
+
+  await fillIn(
+    ".d-editor-input",
+    '[date=2017-10-23 time=01:30:00 format="LL" timezone="Asia/Calcutta" timezones="Europe/Paris|America/Los_Angeles"]'
+  );
+
+  assert.ok(
+    exists(".d-editor-preview .discourse-local-date.past.cooked-date"),
+    "it should contain the cooked date output"
+  );
+});