JUnit testing in Android Studio with Libgdx

I am trying to set up Android Studio to run unit tests with JUnit. I've read several tutorials about setting up testing. I've enabled testing in Android Studio, but I can't get the "test" folder to turn green in my project. I am using Libgdx, which comes with a utility that creates my project structure. It seems to have given me a project structure which is a little unusual (there is no src directory). Since I don't have the src directory, I don't know if that's causing the instructions that I've seen not to work for me. My project structure looks like this:

app java com.my.myprogram myclass1 myclass2

I've tried adding a folder named "test" in various places within my project structure, but with no success. How do I get Android Studio to recognize a folder as my test folder and show it in green in the Project window?