Visual Studio 2015 Unit Test HTTP localhost

I'm using Visual Studio 2015. Creating a stateful API. Because it's using Sessions I cannot use Unit Testing directly to my Controller classes for validation. I need to use HTTP calls.

But when running my Unit Test it doesn't run my project so the HTTP call doesn't find the url http://localhost:54916/api/register

If I run my project and then goto the menu for running Unit Tests it's disabled.

When running my Unit Tests how can I first run the project so that the web/database is online?