Test sanity check example using new interface and inference modules, and put together the first unit test

[StannisZhou]

The unit test should run fast. One option is to cache new results. Another option is to just make the model really small.

In the process, we should also:

1. Deprecate the current contrib module and create a new examples directory to hold everything.
2. Start figuring out what our user facing interface should look like.

[NishanthJKumar]

Just managed to get all the data structures compiled for the 150 x 150 sanity_check example. Looks like it takes 7-9s, whereas the previous naive data-structure compiler took ~5s... Not sure why this is happening - perhaps we should parallelize the new compiler and see? (if you're interested in trying for yourself, notebook is on the sanity_check branch of my fork, under the examples folder)

[StannisZhou]

But I remember for 150x150 examples previously compiling takes about 18s (for the flat implementation). Are you talking about the flat implementation? I can also take a look at the actual code. This implementation is easily parallelizable but even without parallelization I feel it should be at least as fast.....

[NishanthJKumar]

That was for a previous iteration of the compiling code. I refactored it to be faster for the optimized fully-flat implementation. I just tried it and it takes ~6s (test_notebooks/sanity_check_optimize_mpbp_unpadded.py is the test notebook)

[StannisZhou]

Tracking the issue in #18

[StannisZhou]

We can consider adding something like https://github.com/marketplace/codecov to guide our unit test process

[StannisZhou]

Closed via #53