Auto authenticate HTTP authentication in web-based test

I am working with Arquillian Drone and Graphene to write web-based tests for our webapplication. The webapplication uses HTTP authentication. When I start the test (I currently use FirefoxDriver, but I guess it would be the same with every other driver), this login-popup appears to enter the credentials:

Then the test pauses and waits till I type in the credentials manually. How do I make the test automatically use declared credentials and login onto the webpage?

Already have a solution. I pass the credentials directly in the URL.

http://<username>:<password>@url.com