need workaround for authenticating when testing

Tests don't work right now. Since we can't commit credentials for testing purposes, we need a good workaround to allow anyone to run tests. A simple way to do this would be to have a `config.json.dist` file in the test directory and to ignore a local copy of config.json with user credentials. @chelm has a similar solution in https://github.com/ArcGIS/arcgis-js#testing of just including an example auth.js.example file in the test directory and asking users to copy it.