Replaced not easy to use postgres unit test by h2

... also added spring-mockup dependency.
Now, unit tests are running out of the box. 
To check the persisted file based database, just have a look at ~/jdbc-sync-test

or run the h2 console :
java -jar ~/.m2/repository/com/h2database/h2/1.4.182/h2-1.4.182.jar

go to 
http://localhost:8082

and put jdbc-sync-test as dbname

You will get the remaining indeed empty tables (source_table and target table).