Junit - Retornando Erro (ClientTest)

Ao executar o primeiro teste, o JUNIT está retornando o seguinte erro:

javax.ws.rs.ProcessingException: java.lang.IllegalArgumentException: protocol = http host = null
    at org.glassfish.jersey.client.ClientRuntime.invoke(ClientRuntime.java:236)
    at org.glassfish.jersey.client.JerseyInvocation$2.call(JerseyInvocation.java:671)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:228)
    at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:422)
    at org.glassfish.jersey.client.JerseyInvocation.invoke(JerseyInvocation.java:667)
    at org.glassfish.jersey.client.JerseyInvocation$Builder.method(JerseyInvocation.java:396)
    at org.glassfish.jersey.client.JerseyInvocation$Builder.get(JerseyInvocation.java:296)
    at br.com.alura.loja.ClienteTest.testaQueAConexaoComOServidorFunciona(ClienteTest.java:17)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:69)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:48)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:292)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Caused by: java.lang.RuntimeException: java.lang.IllegalArgumentException: protocol = http host = null
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1488)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1474)
    at sun.net.www.protocol.http.HttpURLConnection.getHeaderField(HttpURLConnection.java:3018)
    at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:489)
    at org.glassfish.jersey.client.HttpUrlConnector._apply(HttpUrlConnector.java:276)
    at org.glassfish.jersey.client.HttpUrlConnector.apply(HttpUrlConnector.java:182)
    at org.glassfish.jersey.client.ClientRuntime.invoke(ClientRuntime.java:227)
    ... 32 more
Caused by: java.lang.IllegalArgumentException: protocol = http host = null
    at sun.net.spi.DefaultProxySelector.select(DefaultProxySelector.java:176)
    at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1132)
    at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1032)
    at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:966)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1546)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1474)
    at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480)
    ... 35 more

package br.com.alura.loja;

import javax.ws.rs.client.Client;
import javax.ws.rs.client.ClientBuilder;
import javax.ws.rs.client.WebTarget;

import org.junit.Assert;
import org.junit.Test;


public class ClienteTest {

    @Test
    public void testaQueAConexaoComOServidorFunciona() {
        Client client = ClientBuilder.newClient();
        WebTarget target = client.target("http://www.mocky.io:");
        String conteudo = target.path("/v2/52aaf5deee7ba8c70329fb7d").request().get(String.class);

        Assert.assertTrue(conteudo.contains("<rua>Rua Vergueiro 3185"));
    }
}