Test support library in android studio is not compiled

I have the latest support library instaslled in my sdk. gradle file

defaultConfig {
    applicationId "com.example.win.dat_2"
    minSdkVersion 19
    targetSdkVersion 23
    versionCode 1
    versionName "1.0"
}


buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}

}