Compile on 2.11, introduce settings for dependency versions.

Bump version and make it a snap!shot to 0.4.3-SNAPSHOT.
(Build's version should end in -SNAPSHOT for nightly).

Depend on parser combinators for tests.
Rework Arbitrary instance for Enumeration.
Enable Travis CI

Not testing yet since scalaCheck is not included for 2.11.
This should be remedied as soon as the dbuild configs that
build sbinary also build scalacheck (no reason not to anymore).
Include test dependencies so we can run tests.
Merge pull request #7 from adriaanm/2.11

Compile on 2.11, introduce settings for dependency versions.