Junit 4 does not recognize test

I cloned a repository and tried to run a test. Unfortunately is like junit4 does not recognize the directory that I added manually this is my directory with ExampleUnitTest that i copypasted by another project( is a default file that is not questionable that does not work)

this is my build.gradle

    apply plugin: 'com.android.application'


android {
    compileSdkVersion 23
    buildToolsVersion "23.0.3"

    defaultConfig {
        testApplicationId "com.commonsware.android.retrofit.test"
    }


}

    dependencies {
    compile 'com.squareup.retrofit:retrofit:1.6.1'
    compile 'de.greenrobot:eventbus:2.2.1'
    testCompile 'junit:junit:4.12'
    androidTestCompile 'com.android.support.test:rules:0.4.1'

}