Update build.scala to resolve dependency problem with build.

Build process fails with following error:-

::::::::::::::::::::::::::::::::::::::::::::::
[warn] :: UNRESOLVED DEPENDENCIES ::
[warn] ::::::::::::::::::::::::::::::::::::::::::::::
[warn] :: play#play-iteratees_2.10;2.1.0: not found
[warn] ::::::::::::::::::::::::::::::::::::::::::::::"