Instalei a versão 9.4 do postgress.

pom.xml

 <dependency>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-starter-web</artifactId>
           <version>1.4.1.RELEASE</version>
       </dependency>

       <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
            <version>1.4.2.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>    
            <version>9.4.1212</version>
        </dependency>

Configuração.java

@SpringBootApplication
public class Configuracao {

@Bean
    public DataSource dataSource(){        
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("org.postgresql.Driver");
        dataSource.setUrl("jdbc:postgresql://localhost:5432/teste");
        dataSource.setUsername("postgres");
        dataSource.setPassword("admin");

        return dataSource;
    }

    @Bean
    public Properties additionalProperties() {
        Properties props = new Properties();
        props.setProperty("hibernate.dialect", "org.hibernate.dialect.PostgreSQLDialect");
        props.setProperty("hibernate.show_sql", "true");
        props.setProperty("hibernate.hbm2ddl.auto", "create");
        return props;
    }
}

Usuario.java

package model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity(name="usuario")
public class Usuario {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    private String nome;

    private String email;

    gets and sets