Merge pull request #167 from netiam/greenkeeper/mocha-3.3.0

Update mocha to the latest version 🚀

Merge pull request #160 from netiam/greenkeeper/es6-error-4.0.1

Update es6-error to the latest version 🚀

feat: export stack if `NODE_ENV === 'development'`

fix: export `types` constant, `ErrorType` class and `register` method

chore: use lower version of `babel-cli`

feat: add missing OAuth error codes

fix: add missing error property to method

fix: typo in `Codes.getError`

fix: be fault-tolerant if code has no type

fix: OAuthError must have `error`, `error_description`, `error_uri`,

`state` properties.