Add End-To-End capabilities

[dragonautdev]

As a brunch-with-vuety user I want to be able to start a project using this skeleton and have a basic end-to-end testing configuration done for me, so I can focus on writing tests instead of configuring the project, pretty much the same as vue-cli's generated projects.

Ideally, I'd like to have the setup done using Nightwatch, which while might not be the best framework out there, it is very easy to setup and get up and running.

[dragonautdev]

One of the things that strike me the most about nightwatchjs is its setup, looks convoluted and definitely not ideal for an easy, out of the box setup. Might be a good idea to switch over to Protractor or CucumberJS (which installs all dependencies automatically, including the web driver)