Tests for the Tiler

[frandorr]

We are using the tiler for different tasks and it has been changing a lot. Add tests

• Add 2 or 3 tests to the tiler
• Create a jupyter notebook with the "official" way to use it.

[alkalait]

@frandorr @Lkruitwagen what's the update on this?

[Lkruitwagen]

Discussed with @frandorr - the tiler has an external data dependency, so making a test suite will be cumbersome if we want to avoid increasing the repo size. Deprioritised based on this. Making a jupyter notebook sounds like a decent idea though and not a huge lift! Maybe I'll go ahead and do this for the examples of South Sudan, Nigeria and Mozambique.