Add travis config.
Remove non-test test.

SimpleTest isn't actually a test, and causes lots of problems if we
try to treat it as one :)
Require junit.
... And make the build use the right junit lib ...
Reference junit's dependencies as well.
Merge pull request #2 from csmith/fix-tests

Fix tests
Merge pull request #3 from csmith/travis

Re-add travis config.
Add some defensive checks before casting.