Enhancement: timeseries.fetch() option to fail on no TGT

Created by: areeda

I've had the problem come up that timeseries.fetch() will hang when called in the background (by LDVW) with an expired TGT. This leaves zombie processes.

I can think of 2 approaches that may be easy to implement.

1. A new keyword argument that requests the failure rather than an interactive request for username and password.

2. A timeout, can be long, for the user to enter that information.