Change HelperTest to JUnit4 and remove example test class

app/src/test/java/io/lbry/browser/ExampleUnitTest.java

@@ -1,17 +0,0 @@
-package io.lbry.browser;
-
-import org.junit.Test;
-
-import static org.junit.Assert.*;
-
-/**
- * Example local unit test, which will execute on the development machine (host).
- *
- * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
- */
-public class ExampleUnitTest {
-    @Test
-    public void addition_isCorrect() {
-        assertEquals(4, 2 + 2);
-    }
-}

app/src/test/java/io/lbry/browser/utils/HelperTest.java

@@ -1,7 +1,5 @@
 package io.lbry.browser.utils;
 
-import junit.framework.TestCase;
-
-public class HelperTest extends TestCase {
+public class HelperTest {
 
 }