v2.0.0

Change behaviour so that undefined is returned instead of false if a data reference or answer is not found

v1.0.1

NPM audit security fixes

v1.0.0

Undefined data references are now handled, evaluate as falsey.

v0.4.0

Data references which are undefined in the data object are now evaluated as false.

This allows for evaluation of rules which may be optional or appear conditionally.