jpa EntityManagerProvider depends on hibernate

[rmpestano]

If we use jpa module entityManager provider will throw a class not found exception if hibernate is not on classpath:

Caused by: java.lang.NoClassDefFoundError: org/hibernate/Session
at com.github.dbunit.rules.jpa.EntityManagerProvider.init(EntityManagerProvider.java:63)
at com.github.dbunit.rules.jpa.EntityManagerProvider.instance(EntityManagerProvider.java:48)

this is the line is the cause: https://github.com/rmpestano/dbunit-rules/blob/master/jpa/src/main/java/com/github/dbunit/rules/jpa/EntityManagerProvider.java#L63