solved java project problem.

Crypto/src/ROT13.java

     ROT13() {
     }
 
-
     public String crypt(String text) throws UnsupportedOperationException {
 
         return "";
     }
 
     public static String rotate(String s, Character c) {
-
         return "";
     }
 

Crypto/src/ROT13Test.java → Crypto/test/ROT13Test.java

+import org.junit.Assert;
 import org.junit.Test;
 
 import static org.junit.Assert.*;

SimpleCrypt.iml

+<?xml version="1.0" encoding="UTF-8"?>
+<module org.jetbrains.idea.maven.project.MavenProjectsManager.isMavenModule="true" type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_7">
+    <output url="file://$MODULE_DIR$/target/classes" />
+    <output-test url="file://$MODULE_DIR$/target/test-classes" />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/Crypto/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/Crypto/test" isTestSource="true" />
+      <excludeFolder url="file://$MODULE_DIR$/target" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" scope="TEST" name="Maven: junit:junit:4.12" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.hamcrest:hamcrest-core:1.3" level="project" />
+  </component>
+</module>

pom.xml

     <artifactId>SimpleCrypt</artifactId>
     <version>1.0-SNAPSHOT</version>
 
+    <build>
+        <finalName>example-project</finalName>
+        <pluginManagement>
+            <plugins>
 
+                <!-- v. useful! m2eclipse sometimes fails to see it as a
+                     dynamic web app project in Eclipse. Declaring this plugin
+                     would help eclipse recognize its nature (i.e. a Java
+                     project requesting at least JDK1.7+ -->
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-compiler-plugin</artifactId>
+                    <configuration>
+                        <source>1.7</source>
+                        <target>1.7</target>
+                    </configuration>
+                </plugin>
+
+            </plugins>
+        </pluginManagement>
+    </build>
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>RELEASE</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
 </project>