Refactor and tests based on work under PR #33

Major changes:
- Replace Asteroid DDP (mostly by Jose Renan)
- Convert to promise based socket calls (event emit fallbacks)
- API helpers for Livechat
- Test coverage for DDP and driver
- Driver methods deprecated in favour of DDP

Minor changes:
- `subscribeToMessages` not required to `respondToMessages`
- Add contributors to package
- New interfaces for better intellisense
- Debugging in vscode
- Add utils lib for shared functions
- Use browser bundle friendly deps
- Put all interfaces together
- Use valid but throw-away email
- Use implicit function return typing
- Depreciated methods that proxy DDP