Erro ao acessar o banco...

Tive o erro ao acessar a base de dados, alterei no meu arquivo de propriedades para o endereço do Amazon, (não sei se está correto):

jdbc.url = jdbc:mysql://ec2-54-144-220-4.compute-1.amazonaws.com:3306/contas

Minha Classe SpringDataConfig Está assim:

package br.com.clipboard.financeiro.config;

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

import org.apache.commons.dbcp2.BasicDataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.HibernateJpaDialect;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration
@EnableJpaRepositories("br.com.clipboard.financeiro.repository")
@EnableTransactionManagement
@PropertySource("classpath:/application.properties")
public class SpringDataConfig {

    @Autowired
    private Environment env;

    @Bean
    public PlatformTransactionManager transactionManager(EntityManagerFactory factory) {
        JpaTransactionManager manager = new JpaTransactionManager();
        manager.setEntityManagerFactory(factory);
        manager.setJpaDialect(new HibernateJpaDialect());
        return manager;
    }

    @Bean
    public HibernateJpaVendorAdapter JpaVendorAdapter() {
        HibernateJpaVendorAdapter adapter = new HibernateJpaVendorAdapter();
        adapter.setShowSql(env.getProperty("hibernate.show.sql", Boolean.class));
        adapter.setGenerateDdl(env.getProperty("hibernate.ddl", Boolean.class));
        return adapter;
    }

    @Bean
    public EntityManagerFactory entityManagerFactory() {
        LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
        factory.setJpaVendorAdapter(JpaVendorAdapter());
        factory.setPackagesToScan(
                env.getProperty("hibernate.package.scan"),
                env.getProperty("java.time.jpa.converter")
        );
        factory.setDataSource(dataSource());
        factory.afterPropertiesSet();        
        return factory.getObject();
    }

    @Bean(name = "dataSource")
    public DataSource dataSource() {
        BasicDataSource dataSource = new BasicDataSource();
        dataSource.setUsername(env.getProperty("jdbc.user"));
        dataSource.setPassword(env.getProperty("jdbc.pass"));
        dataSource.setDriverClassName(env.getProperty("jdbc.driverClass"));
        dataSource.setUrl(env.getProperty("jdbc.url"));
        return dataSource;
    }
}

e estou tendo o erro:

Caused by: org.springframework.beans.factory.BeanCreationException: Error creati                                                                                                 ng bean with name 'entityManagerFactory' defined in class path resource [br/com/                                                                                                 clipboard/financeiro/config/SpringDataConfig.class]: Bean instantiation via fact                                                                                                 ory method failed; nested exception is org.springframework.beans.BeanInstantiati                                                                                                 onException: Failed to instantiate [javax.persistence.EntityManagerFactory]: Fac                                                                                                 tory method 'entityManagerFactory' threw exception; nested exception is org.hibe                                                                                                 rnate.HibernateException: Access to DialectResolutionInfo cannot be null when 'h                                                                                                 ibernate.dialect' not set

Qual o caminho da base de dados correta? Onde estou errando aqui?