* Remove expired credentials (Ryan Graham)

 * Update storage-service.js (Tony Sukiennik)

 * Update index.js (Tony Sukiennik)

 * Allow the Sample to easily changed providers (tonysoft)

 * GetFiles issues (tonysoft)

 * Add contribution guidelines (Ryan Graham)

 * Put link to official documentation (Rand McKinney)

 * Add loopback 2.0 example (Raymond Feng)

 * Clarify the need for app.model(container) (Brian Dunnette)