- set sequential on the ApplicationSpec to fix maybe broken travis build
- to get less logging during test phase implements clearProperty for the c3p0 logging system preoprties
- use play test instead of play coveralls

The travis build is broken during coveralls run with
Could not create directory /home/travis/build/pussinboots/bankapp/target/scala-2.10/classes.bak.
They are also bokren tests at the moment first fix the test problem than the coveralls problem.