There is now support for an in-memory cookie store. This feature can be

enabled via the --in-memory-cookies command-line option. For

consumers of the API, passing in_memory_cookies=True to the RBClient

constructor will enable this behaviour as well.

Ran unit tests.
Updated this review request with the --in-memory-cookies flag. I was

prompted for my username and password. When updating without the flag,

I am not prompted.