fixing mockito version and start of espresso native e2e

android/app/build.gradle

     testCompile 'junit:junit:4.12'
     testCompile 'org.robolectric:robolectric:3.2.2'
     testCompile 'org.assertj:assertj-core:2.5.0'
-    // required for robolectric
-    testCompile 'org.khronos:opengl-api:gl1.1-android-2.1_r1'
+    testCompile 'org.mockito:mockito-core:2.7.5'
 
-    testCompile 'org.mockito:mockito-core:2.+'
+    // native e2e
+    androidTestCompile 'com.android.support.test.espresso:espresso-core:2.2.2'
 }

android/app/src/test/java/com/reactnativenavigation/ApplicationTest.java

+package com.reactnativenavigation;
+
+import org.junit.Test;
+
+import static org.assertj.core.api.Java6Assertions.assertThat;
+
+public class ApplicationTest {
+    @Test
+    public void startingActivity() {
+        assertThat(1+2).isNotZero();
+    }
+}

android/prepare-robolectric.gradle

 configurations.create('robolectricRuntime')
 
 dependencies {
+    testCompile "org.khronos:opengl-api:gl1.1-android-2.1_r1"
     robolectricRuntime "org.robolectric:android-all:6.0.1_r3-robolectric-0"
     robolectricRuntime "org.robolectric:shadows-core:3.2.2"
 }