cleanup and update to 4.2.0

This PR updates bootbox to 4.2.0 and does some additional cleanup:

- Removed the extraneous `.meteor` folder which was pointing to something on @TimHeckel's local machine
- Removed `smart.lock` from the repo and put it in `.gitignore`; this shouldn't be in a smart package.
- Updated version in `smart.json` and added an explicit dependency for Meteorite to install bootstrap 3