This is a work-around until Bug 1405889 is deployed. Using the /bewit
endpoint does have the advantage of avoiding another issue in
taskcluster-proxy, namely that the /bewit approach streams. Fetching
through the proxy does not stream from the upstream resource; the
upstream resource is fetched and stored in taskcluster-proxy's memory,
increasing operational costs.
MozReview-Commit-ID: 8yS7zKLALhd