ENYO-831: rename DropboxConfig into DropboxAuthConfig
ENYO-831: rename DropboxConfig into DropboxAuthConfig

- this time with package.js...
- follow the same naming conventions as BasicAuthConfig

Enyo-DCO-1.1-Signed-off-by: Francois-Xavier KOWALSKI <francois-xavier.kowalski@hp.com>

enyojs/ares-project,mcanthony/ares-project,mcanthony/ares-project,enyojs/ares-project,enyojs/ares-project,enyojs/ares-project,mcanthony/ares-project,mcanthony/ares-project,enyojs/ares-project,mcanthony/ares-project,mcanthony/ares-project