E2E test job

In this video, we'll create a job for our E2E tests. This job will be the most complicated of all our jobs so far as we need not only Mongo DB, but also Selenium and headless Chrome in our CD environment.

So let's begin by creating a new job e2e-test. We'll add a stage property and add it to the test stage. We'll add the only property and add an array member deploy to ensure this job is only run for the deploy branch.