iluwatar#539 More Checkstyle fixes

Author: iluwatar

converter/src/test/java/com/iluwatar/converter/AppTest.java

@@ -24,6 +24,9 @@
 
 import org.junit.Test;
 
+/**
+ * App running test
+ */
 public class AppTest {
 
   @Test

converter/src/test/java/com/iluwatar/converter/ConverterTest.java

@@ -31,6 +31,9 @@
 
 import static junit.framework.TestCase.assertEquals;
 
+/**
+ * Tests for {@link Converter}
+ */
 public class ConverterTest {
 
   private UserConverter userConverter = new UserConverter();