Android Command Line Testing with Gradle

Ok, I have been researching this for multiple days now and dug up some good resources like this user guide. I can also build and install just fine thanks to this guy. However, I cannot, for the life of me, figure out how to run my instrumentation tests without having a connected device.

Is it simply not possible to run the tests under app/src/androidTest (where I have most of my tests) without using the command ./gradlew connectedAndroidTest?

Also, I've seen it's recommended to put jUnit tests under app/src/test and Instrumentation tests under the gradle preconfigured app/src/androidTest. Is this a good way to set up the app's tests, even though that means creating two different testing directories?

I'm asking all of this because I'm using a Jenkins CI job to build the Android project upon the code being updated and I'd like Jenkins to run all of my tests along with building the project, but I'd hope I wouldn't have to concern myself with creating some sort of emulator/device for Jenkins to run the tests on (as required by ./gradlew connectedAndroidTest).