Fix and refactor BooksIntegrationTest

the BooksIntegrationTest file was commented out on Feb 4, 2013
https://github.com/perwendel/spark/commit/6e3ae33818d01a3287a4b3ff16274d3f65f5b505

The tests were failing, interwoven, depended on each other, used
deprecated junit methods and methods that were removed from the Spark API.

I fully cleaned them up and used the new Lambda-Syntax. All the assertions were kept the same, none were removed.