A special config file for use when developing `kraken-js`

By default, the `development.json` config file was selected when running tests, but the settings for dev mode of an application may be different from settings needed to run unit tests against kraken. Therefore the special NODE_ENV and subsequent config file `_krakendev.json` was created containing any necessary custom settings.

Additionally, this PR fixes issue #200 by removing the default `dust` setting for `express:view engine`.