Switch to WebdriverIO browser tests

This project currently seems to use Karma for their browser tests. Today WebdriverIO has its own browser runner that allows to run Unit and/or component tests in the browser, locally or on Sauce.

I am happy to take a stab at updating the test setup to run browser tests in WebdriverIO.

What do you think?

Start by locating the current Karma browser-test setup and identifying how unit and component tests are invoked. Compare that entry point with WebdriverIO's browser runner, including local and Sauce execution. Done means the existing browser tests run through WebdriverIO in both supported environments.

Written by the indexing model from the issue text.