Test suite

[abooij]

It would be nice to have some unit testing and quickcheck-based property testing for our library. The libwayland developers are currently struggling to do anything in this direction, so this would be a big step forward from our side.

I'm not sure how to get started with this. WireMessage and WirePackage encode/decode tests seem obvious, but their API might change according to #6. And sudbury's Haskell API is still a bit in development, see #2. Suggestions are welcome.

[abooij]

Apart from encode/decode tests, we should also have tests for object lifetime and protocol versions.

[abooij]

I haven't made any progress here because it would require being able to build this project on Travis, which would mean requiring to use a development version of Cabal on Travis (as we require cabal-install >= 1.25). However, it seems like Cabal 2.0 might be getting a release "soon" so that would perhaps make this easier.

Or perhaps we can do unit testing with Cabal 1.24? This would prevent us from building the shared object on Travis, but that doesn't prevent us from doing unit testing...