Estoy tratando de integrar la tecnología roboeléctrica en mi nuevo proyecto. Utilicé los siguientes enlaces para comprender e implicar la tecnología roboeléctrica

http://pivotallabs.com/setting-up-robolectric-in-android-studio-1-1-on-os-x/

http://nenick-android.blogspot.in/2015/02/android-studio-110-beta-4-and.html

http://raptordigital.blogspot.in/2014/02/test-driven-development-with.html

Pero recibo el siguiente error al ejecutar mi clase de prueba

Error:Gradle: Execution failed for task ':app:compileDebugJava'.
> Compilation failed; see the compiler error output for details.
E:\junitTest\android-studio-robolectric-example-master\JunitTestApp\app\src\test\java\com\inapp\junittestapp\SampleTest.java
Error:(7, 17) Gradle: error: package org.junit does not exist
 Error:(8, 24) Gradle: error: package org.junit.runner does not exist
Error:(9, 23) Gradle: error: package org.robolectric does not exist
 Error:(10, 34) Gradle: error: package org.robolectric.annotation does not exist
Error:(11, 31) Gradle: error: package org.robolectric.shadows does not exist
Error:(13, 27) Gradle: error: package org.hamcrest does not exist
Error:(13, 1) Gradle: error: static import only from classes and interfaces
Error:(14, 27) Gradle: error: package org.hamcrest does not exist
Error:(14, 1) Gradle: error: static import only from classes and interfaces
Error:(15, 24) Gradle: error: package org.junit does not exist
Error:(15, 1) Gradle: error: static import only from classes and interfaces
Error:(16, 30) Gradle: error: package org.robolectric does not exist
Error:(16, 1) Gradle: error: static import only from classes and interfaces
Error:(17, 30) Gradle: error: package org.robolectric does not exist
Error:(17, 1) Gradle: error: static import only from classes and interfaces
Error:(18, 30) Gradle: error: package org.robolectric does not exist
Error:(18, 1) Gradle: error: static import only from classes and interfaces
Error:(25, 2) Gradle: error: cannot find symbol class RunWith
Error:(26, 2) Gradle: error: cannot find symbol class Config
Error:(30, 6) Gradle: error: cannot find symbol class Test
Error:(32, 38) Gradle: error: cannot find symbol method      setupActivity(Class<MainActivity>)
Error:(36, 9) Gradle: error: cannot find symbol method clickOn(Button)
Error:(38, 41) Gradle: error: cannot find symbol variable ShadowAlertDialog
Error:(39, 42) Gradle: error: cannot find symbol method notNullValue()
Error:(41, 9) Gradle: error: cannot find symbol class ShadowAlertDialog
Error:(41, 47) Gradle: error: cannot find symbol method shadowOf(AlertDialog)
Error:(42, 61) Gradle: error: cannot find symbol method is(String)

Agregado debajo de mi código de clase de prueba

import android.app.AlertDialog;
import android.widget.Button;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.robolectric.RobolectricTestRunner;
import org.robolectric.annotation.Config;
import org.robolectric.shadows.ShadowAlertDialog;

import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.CoreMatchers.notNullValue;
import static org.junit.Assert.assertThat;
import static org.robolectric.Robolectric.clickOn;
import static org.robolectric.Robolectric.setupActivity;
import static org.robolectric.RobolectricBase.shadowOf;


@RunWith(RobolectricTestRunner.class)
@Config(manifest = "app/src/main/AndroidManifest.xml", emulateSdk = 18)
public class SampleTest {

    @Test
    public void buttonTapDisplaysAnAlertDialog() {
        MainActivity helloActivity = setupActivity(MainActivity.class);

        Button button = (Button) helloActivity.findViewById(R.id.button);

        clickOn(button);

        AlertDialog latestAlertDialog = ShadowAlertDialog.getLatestAlertDialog();
        assertThat(latestAlertDialog, is(notNullValue()));

        ShadowAlertDialog shadowAlertDialog = shadowOf(latestAlertDialog);
        assertThat(shadowAlertDialog.getTitle().toString(), is("Hi"));
    }

}

y mi archivo gradle de aplicaciones es

    apply plugin: 'com.android.application'

android {
    compileSdkVersion 22
    buildToolsVersion "21.1.2"

    defaultConfig {
        applicationId "com.example.junittestapp"
        minSdkVersion 15
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    sourceSets { main { java.srcDirs = ['src/main/java', 'src/test/java/'] } }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    compile 'com.android.support:support-v4:22.1.1'
    testCompile 'junit:junit:4.12'
    testCompile 'org.robolectric:robolectric:2.4'
}

También encontré el mismo error en este blog

https://discuss.gradle.org/t/why-cant-my-simplest-one-line-build-gradle-compile-tests-with-junit-jar/1868

Creo que extraño algo. Cualquier ayuda será apreciada.