Mensagem de erro ao rodar JUNIT

package Caelum;

import static org.junit.Assert.assertTrue;

import org.junit.Test;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;

public class UsuariosSystemTest {
    @Test
    public void deveAdicionarUmUsuario(){
        System.setProperty("webdriver.gecko.driver","c:\\geckodriver.exe");
        WebDriver driver = new FirefoxDriver();
        driver.get("http://localhost:8080/usuarios/new");

        WebElement nome =  driver.findElement(By.name("usuario.nome"));
        WebElement email =  driver.findElement(By.name("usuario.email"));

        nome.sendKeys("Jackson Praia Brandão");
        email.sendKeys("jacksonbrandaobr@gmail.com");

        WebElement botaoSalvar = driver.findElement(By.id("btnSalvar"));
        botaoSalvar.click();

        // garantir que Ronaldo foi adicionado!
        boolean achouNome = driver.getPageSource().contains("Jackson Praia Brandão");
        boolean achouEmail = driver.getPageSource().contains("jacksonbrandaobr@gmail.com");

        assertTrue(achouNome);
        assertTrue(achouEmail);

        driver.close();


    }
}

-------------- MENSAGEM DE ERRO --------------------

java.lang.NoClassDefFoundError: org/hamcrest/SelfDescribing

    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:335)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at org.junit.internal.builders.JUnit4Builder.runnerForClass(JUnit4Builder.java:10)
    at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
    at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26)
    at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
    at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:33)
    at org.junit.internal.requests.FilterRequest.getRunner(FilterRequest.java:36)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:49)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.lang.ClassNotFoundException: org.hamcrest.SelfDescribing
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:335)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 22 more