Curso Spring MVC 2 - Criando aplicações WEB - Erro na execução do teste

Prezados,

Ao tentar realizar os testes, da aula 7, deu a seguinte menagem:

java.lang.IllegalStateException: Failed to load ApplicationContext
    at org.springframework.test.context.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:91)
...
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class br.com.casadocodigo.loja.conf.DataSourceConfigurationTest: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public javax.sql.DataSource br.com.casadocodigo.loja.conf.DataSourceConfigurationTest.dataSource()] threw exception; nested exception is java.lang.IllegalStateException: Could not load JDBC driver class [com.mysql.jdbc.driver]

A minha classe JPAConfiguration:

package br.com.casadocodigo.loja.conf;

import java.util.Properties;

import javax.persistence.EntityManagerFactory;
import javax.sql.DataSource;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Profile;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.JpaVendorAdapter;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@EnableTransactionManagement
public class JPAConfiguration {

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory(DataSource dataSource) {
        LocalContainerEntityManagerFactoryBean factoryBean = 
            new LocalContainerEntityManagerFactoryBean();
        JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();

        factoryBean.setJpaVendorAdapter(vendorAdapter);
        factoryBean.setDataSource(dataSource);

        Properties props = aditionalProperties();

        factoryBean.setJpaProperties(props);
        factoryBean.setPackagesToScan("br.com.casadocodigo.loja.model");

        return factoryBean;
    }

    @Bean
    @Profile("dev")
    public DataSource dataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setUsername("root");
        dataSource.setPassword("mysql");
        dataSource.setUrl("jdbc:mysql://localhost:3306/casadocodigo");
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        return dataSource;
    }

    private Properties aditionalProperties() {
        Properties props = new Properties();
        props.setProperty("hibernate.dialect", "org.hibernate.dialect.MySQL5Dialect");
        props.setProperty("hibernate.show_sql", "true");
        props.setProperty("hibernate.hbm2ddl.auto", "update");
        return props;
    }

    @Bean
    public JpaTransactionManager transactionManager(EntityManagerFactory emf) {
        return new JpaTransactionManager(emf);
    }

}

Eu encontrei a seguinte thread no site da ALURA, mas não entendi qual foi a solução dada.

https://cursos.alura.com.br/forum/topico-erro-na-importacao-do-projeto-34638