Only bail on 401s after attempting to fetch current user

if another 401 occurs when fetching the current user, then we know we
have a problem and should bail.
Merge pull request #112 from derrh/jsonapi-support

Only bail on 401s after attempting to fetch current user
Merge pull request #113 from instructure/jsonapi-support

Adding an additional check on 401 errors before forcing a logout.