Update junit version to 4.13-beta-2

This will allow us to use @BeforeParam which plays more nicely into
the new testparameter setup when we only one to run a single point,
which is the normal case in IntelliJ

Change-Id: I96c7eb61507ca7f7c886cd5d08b05bfc372c5d35
diff --git a/build.gradle b/build.gradle
index 1a7de42..3385270 100644
--- a/build.gradle
+++ b/build.gradle
@@ -37,7 +37,7 @@
     guavaVersion = '23.0'
     joptSimpleVersion = '4.6'
     gsonVersion = '2.7'
-    junitVersion = '4.12'
+    junitVersion = '4.13-beta-2'
     mockitoVersion = '2.10.0'
     kotlinVersion = '1.3.11'
     kotlinExtMetadataJVMVersion = '0.0.4'
diff --git a/src/test/java/com/android/tools/r8/debuginfo/InliningWithoutPositionsTestRunner.java b/src/test/java/com/android/tools/r8/debuginfo/InliningWithoutPositionsTestRunner.java
index 980325e..0588b33 100644
--- a/src/test/java/com/android/tools/r8/debuginfo/InliningWithoutPositionsTestRunner.java
+++ b/src/test/java/com/android/tools/r8/debuginfo/InliningWithoutPositionsTestRunner.java
@@ -94,7 +94,7 @@
   @Test
   public void testStackTrace() throws Exception {
     // See InliningWithoutPositionsTestSourceDump for the code compiled here.
-    Path testClassDir = temp.newFolder(TEST_PACKAGE.split(".")).toPath();
+    Path testClassDir = temp.newFolder().toPath();
     Path testClassPath = testClassDir.resolve(TEST_CLASS + ".class");
     Path outputPath = temp.newFolder().toPath();
 
diff --git a/src/test/java/com/android/tools/r8/debuginfo/PreamblePositionTestRunner.java b/src/test/java/com/android/tools/r8/debuginfo/PreamblePositionTestRunner.java
index 14f9f98..90239e7 100644
--- a/src/test/java/com/android/tools/r8/debuginfo/PreamblePositionTestRunner.java
+++ b/src/test/java/com/android/tools/r8/debuginfo/PreamblePositionTestRunner.java
@@ -37,8 +37,7 @@
   }
 
   private void testBothBranches(boolean invertConditionals) throws Exception {
-    Path testClassDir = temp.newFolder(TEST_PACKAGE.split(".")).toPath();
-    Path testClassPath = testClassDir.resolve(TEST_CLASS + ".class");
+    Path testClassPath = temp.newFolder().toPath().resolve(TEST_CLASS + ".class");
     Path outputDexPath = temp.newFolder().toPath();
 
     Files.write(testClassPath, PreamblePositionTestSourceDump.dump());