Keep unit tests' temporary directories around

Now that we use SciJava common's TestUtils, the temporary directories
are guaranteed to be in the target/ directory. So let's keep them
around for further inspection after tests ran.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

src/test/java/org/scijava/plugins/scripting/java/JavaEngineTest.java

@@ -97,7 +97,6 @@ public void minimalProjectFromPOM() throws Exception {
 		assertTrue(jar.exists());
 
 		System.gc();
-		assertTrue(FileUtils.deleteRecursively(dir));
 	}
 
 	@Test
@@ -134,7 +133,6 @@ public void minimalProjectFromSource() throws Exception {
 		assertTrue(jar.exists());
 
 		System.gc();
-		assertTrue(FileUtils.deleteRecursively(dir));
 	}
 
 	@Test

src/test/java/org/scijava/plugins/scripting/java/MakeJarTest.java

@@ -44,6 +44,7 @@
 import java.util.jar.JarFile;
 
 import org.junit.Test;
+import org.scijava.test.TestUtils;
 import org.scijava.util.FileUtils;
 import org.scijava.util.IteratorPlus;
 
@@ -53,7 +54,8 @@ public void testSingle() throws Exception {
 		final StringWriter writer = new StringWriter();
 		final JavaEngine engine = new JavaEngine();
 		final File file = FileUtils.urlToFile(getClass().getResource("/Dummy.java"));
-		final File output = File.createTempFile("jar-test-", ".jar");
+		final File tmpDir = TestUtils.createTemporaryDirectory("jar-test-");
+		final File output = new File(tmpDir, "test.jar");
 		engine.makeJar(file, false, output, writer);
 		assertJarEntries(output, "META-INF/MANIFEST.MF",
 				"META-INF/maven/net.imagej/Dummy/pom.xml", "Dummy.class");