Travis is not running tests

[smolkaj]

Because of some bug in the oasis or Makefile, Travis is not actually running the tests at the moment. That kind of defeats the purpose...

And indeed, a bunch of them are broken. We should fix this.

[smolkaj]

A related problem is that the examples in examples/ are not tested automatically. We should set it up so that all examples are executed and checked for non-zero exit status.

[smolkaj]

The same is true for ppx/test.