added jpa classes (mostly from http://spring.io/guides/tutorials/data)
Getting warning: H2EmbeddedDatabaseConfigurer - Could not shutdown embedded database
                 org.h2.jdbc.JdbcSQLException: Database is already closed (to disable automatic closing at VM shutdown, add ";DB_CLOSE_ON_EXIT=FALSE" to the db URL) [90121-173]
fixed H2 shutdown error