Set up testing

[nsbgn]

Dependencies: #3

At the moment, there are no automated tests for this part of the pipeline. Any improvements made to one part might cause a regression elsewhere (see also #1).

We will need tests at these levels:

1. A tool that builds blocks from a natural language question, to test whether all corpus questions can still be built as blocks.
2. Tests to check whether functional roles are correctly extracted from blocks.
3. Tests to check whether transformation graphs with core concepts are correctly generated from functional roles.
4. Tests to check whether transformation graphs with CCT types are correctly identified from transformation graphs with core concepts.

I'm not yet familiar with JavaScript's testing ecosystem. Updates will be tracked here.