Android JUnit Testing, cannot resolve is(boolean) in assertThat?

in build.gradle

dependencies {    
    testCompile 'junit:junit:4.12'
    testCompile 'org.mockito:mockito-core:1.10.19'
}

Code

import com.myapp.LVActivity;
import org.junit.Test;
import static org.junit.Assert.*;

public class DeviceUnitTest {
    @Test
    public void check_that_is_correct_device_name_isTrue() {
        assertThat(LVActivity.isCorrectDevice("MySpecialDevice"), is(true));
    }
}

In LVActivity:

private final static String correctName = "MySpecialDevice";
public static boolean isCorrectDevice(String deviceName) {
    return deviceName.equals(correctName);
}

The error is here:

is(true)

Error:

Cannot resolve method is(boolean)

I am trying to do a simple local unit test.

I'm following this tutorial http://ift.tt/1d454hx