0.17.x

Separate release branch for 0.17.x version, to continue to be developed until the big refactor is complete and 0.20.0 is released. Will be published as [npm/asimov.js](https://www.npmjs.org/package/asimov.js), and the new refactored version is published as [npm/asimov](https://www.npmjs.org/package/asimov).