Mesmo alterando continuei com o mesmo erro.
package br.com.caelum.financas.modelo;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
@Entity
public class Conta {
    @Id @GeneratedValue(strategy=GenerationType.IDENTITY)
    private Integer id;
    private String titular;
    private String numero;
    private String banco;
    private String agencia;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getTitular() {
        return titular;
    }
    public void setTitular(String titular) {
        this.titular = titular;
    }
    public String getNumero() {
        return numero;
    }
    public void setNumero(String numero) {
        this.numero = numero;
    }
    public String getBanco() {
        return banco;
    }
    public void setBanco(String banco) {
        this.banco = banco;
    }
    public String getAgencia() {
        return agencia;
    }
    public void setAgencia(String agencia) {
        this.agencia = agencia;
    }
}
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
    version="2.0">
    <!-- unidade de persistencia com o nome financas -->
    <persistence-unit name="financas">
        <!-- Implementação do JPA, no nosso caso Hibernate -->
        <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
        <!-- Aqui são listadas todas as entidades -->
        <class>br.com.caelum.financas.modelo.Conta</class>
        <properties>
            <!-- Propriedades JDBC -->
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost/financas" />
            <property name="javax.persistence.jdbc.user" value="root" />
            <property name="javax.persistence.jdbc.password" value="" />
            <!-- Configurações específicas do Hibernate -->
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect" />
            <property name="hibernate.hbm2ddl.auto" value="update" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.format_sql" value="true" />
        </properties>
    </persistence-unit>
</persistence>
package br.com.caelum.financas.modelo;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
@Entity
public class Conta {
    @Id @GeneratedValue(strategy=GenerationType.IDENTITY)
    private Integer id;
    private String titular;
    private String numero;
    private String banco;
    private String agencia;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getTitular() {
        return titular;
    }
    public void setTitular(String titular) {
        this.titular = titular;
    }
    public String getNumero() {
        return numero;
    }
    public void setNumero(String numero) {
        this.numero = numero;
    }
    public String getBanco() {
        return banco;
    }
    public void setBanco(String banco) {
        this.banco = banco;
    }
    public String getAgencia() {
        return agencia;
    }
    public void setAgencia(String agencia) {
        this.agencia = agencia;
    }
}
abr 03, 2017 4:23:41 PM org.hibernate.jpa.boot.internal.PersistenceXmlParser doResolve
INFO: HHH000318: Could not find any META-INF/persistence.xml file in the classpath
Exception in thread "main" javax.persistence.PersistenceException: No Persistence provider for EntityManager named financas
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:61)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:39)
    at br.com.caelum.financas.teste.TesteJPA.main(TesteJPA.java:19)