Já vi que muitos postaram esse problema aqui, mas as soluções apresentadas não foram suficientes para resolver o meu problema. Seguindo o exemplo do curso de SpringBoot aula do segundo capitulo
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: javassist/bytecode/ClassFile
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1578) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1054) ~[spring-context-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:829) ~[spring-context-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538) ~[spring-context-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) ~[spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:760) [spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
at org.springframework.boot.SpringApplication.createAndRefreshContext(SpringApplication.java:360) [spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:306) [spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1185) [spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1174) [spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
at br.com.ehs.Configuracao.main(Configuracao.java:14) [classes/:na]
Caused by: java.lang.NoClassDefFoundError: javassist/bytecode/ClassFile