Use Javascript test runner

Migrate to a javascript test runner.

- remove Ruby, RubyGems, and Bundler dependency
- add Node and NPM dependency
- remove development dependency on globally installed tools
- add development dependencies to package file for local install

```
- npm install  // install dependencies locally
- npm test     // single run (for CI/CD)
- npm run watch    // watch files for changes, then run tests
```