Changes:

- Added `boom` as a dependency
- Added support for creating `boom` errors
- Updated linter rules and fixed linter warnings/errors
- Removed `gjslint` as the default linter in favor of `eslint`
- Switch assertion library from `should` to `chai`
- Refactored the error factory class to be based on `boom`
- Added tests to reflect the changes in `error_factory`
- Bumped version to `0.3.0`