api request to download package breaks when "accept" is "application/octet-stream"

[noa]

when trying to use the api to download a package:
GET v1/catalog/packages/{id}/download with "accept" header "application/octet-stream"
you get a response code 415 with an "Unsupported Content-Type" message.
this used to work before, and should work,
since the documentation states that the response is of type application/octetstream: ("Response 200 (application/octetstream)").

a possible simple fix is adding the "application/octet-stream" to the default accept types. (see attached patch)
if this change is acceptable I can push the fix.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/213706

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/213706
Committed: https://git.openstack.org/cgit/openstack/murano/commit/?id=fdec9e04ad2f2fc27b2cd2ac92a4fa16a3f7f28c
Submitter: Jenkins
Branch: master

commit fdec9e04ad2f2fc27b2cd2ac92a4fa16a3f7f28c
Author: noa <email address hidden>
Date: Mon Aug 17 13:33:30 2015 +0000

    Fixing support for package download API.

    Adding "application/octet-stream" to default_accept_types
    in order to allow calling the package download api with
    the header "accept"="application/octet-stream".
    Adding test for the fix, including negative test with
    bad accept type.

    Change-Id: I682e312b24183354b62fe10f45c412bf65e4f71e
    Closes-Bug: #1485480