Allow for user to reset token mid-crawl

[tskluzac]

See error:
2020-01-15 20:13:25,231 - Caught error : (401, 'AuthenticationFailed', 'Token is not active', 'E4MtgqmLj')

Tens of thousands of files into a crawl, we have to throw it away and start over because we happened to launch the crawl AFTER the token expired. What we should do is either

(A) Find a way to implement refresh tokens? (not sure if helpful here--need to follow up).
(B) Allow user to re-submit their credential.

[tskluzac]

This will be best accomplished by catching the API Auth errors, saving all current state to S3, and then creating a 'resume' mode on the crawl id (with new 'headers')