Similar to drop_shared. The difference is that this bypasses the
Dropbox webserver, used to provide a preview of the file, so that you can
effectively stream the contents of your media. This URL should not be used to
display content directly in the browser. IMPORTANT: The media link will expire
after 4 hours. So you'll need to cache the content with knitr cache OR re-run
the function call after expiry.
The Dropbox token generated by drop_auth. rdrop2
will try to automatically locate your local credential cache and use them.
However, if the credentials are not found, the function will initiate a new
authentication request. You can override this in drop_auth by
pointing to a different location where your credentials are stored.