First crude benchmarking attempt.
First attempt at run hook implementation.
Initial after_run hook implementation.
First pass at before/after row hooks.
Refactor step hook tests.
Use a hookable module for establishing hooks.
Use observer pattern to extract step behavior and allow customg run hooks.
Refactor example for use inheritance chain.
No need for a finalize method now that there's hooks.
Add observation behavior to the Transformation class.
Version bump.