Added dependencies
Adapted ApplicationConfiguration
Implemented JpaConfiguration (see Link1)
Implemented JpaAssertions for easier testing (see Link1)

Link1: http://spring.io/guides/tutorials/data/3/#user-content-start-with-a-failing-test-introducing-jpa for details.

#IAA-43 frederic.oppermann in progress work development 1h30m documentation reading and implementation
Annotated User for persistence.
#IAA-43 work development 1h15m much documentation reading and a bit development
added dependencies for slf4j and h2 database.
implemented test to check that tables exist in database.
fixed a bug in JpaConfiguration and added a web- and a tcp-server to be able to access the h2 embedded database while the application is running.
#IAA-43 work development 2h reading documentation and developing
renamed JPAConfiguration.java to JpaConfiguration.java.
ApplicationConfiguration imports JpaConfiguration.
User attributes are not nullable columns.
#IAA-43 work development 1h reading documentation and developing
Implemented SpringRepository.
#IAA-43 ready to merge work development 1h45m unfortunately I spend a lot of time on bug hunting. Repository was not generated by Spring. Frist problem was @Repository Annotation on the interface, second was a bad base package for Repository search.
Merge branch 'IAA-43' into development
#IAA-43 fixed work 5m