added test method

src/test/java/teetime/framework/pipe/SingleElementPipeTest.java

+package teetime.framework.pipe;
+
+import static org.junit.Assert.assertFalse;
+
+import org.junit.Test;
+
+public class SingleElementPipeTest {
+
+	@Test(expected = IllegalArgumentException.class)
+	public void testAdd() throws Exception {
+		SingleElementPipe pipe = new SingleElementPipe(null, null);
+		assertFalse(pipe.add(null));
+	}
+
+}