Use JUnit4 for skylark tests.

--
Change-Id: I3cf7a8127da60d93005594d73abbdb8f7bda7cf2
Reviewed-on: https://bazel-review.googlesource.com/#/c/2041
MOS_MIGRATED_REVID=103940423
diff --git a/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java b/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
index d027adb..f956f94 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
@@ -30,6 +30,7 @@
 import com.google.devtools.build.lib.syntax.ClassObject.SkylarkClassObject;
 import com.google.devtools.build.lib.testutil.TestMode;
 
+import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
@@ -39,7 +40,8 @@
  */
 @RunWith(JUnit4.class)
 public class SkylarkEvaluationTest extends EvaluationTest {
-  public SkylarkEvaluationTest() throws Exception {
+  @Before
+  public void setup() throws Exception {
     setMode(TestMode.SKYLARK);
   }