This commit addresses an issue where the Content-Type header is not
being set correctly in the response. This has been fixed in Swift v1.9.
openstack/swift@ad24cde120
The tests have also been updated so they don't rely on changes in Swift v1.9
that affect the response body when errors are reported.
openstack/swift@6768d5b4be
Renames the current #put_object_manifest method to better differentiate
this from the new #put_static_obj_manifest method. #put_object_manifest
has been retained for backward compatibility.