swift_operator_role defaults to "Member", not "member"

[Dmitrii Shcherbakov]

The default bootstrap process adds "member" (lowercase "m") not "Member".

https://docs.openstack.org/keystone/latest/admin/case-insensitive.html#roles

Tempest was changed to have a lowercase default:
https://opendev.org/openstack/tempest/commit/99d4dae684
https://bugs.launchpad.net/tempest/+bug/1330132

Not doing that may result in errors such as this:
https://paste.ubuntu.com/p/jWwjTPHkHP/
2020-06-23 19:11:43.307 23920 ERROR rally keystoneauth1.exceptions.http.Conflict: Conflict occurred attempting to store role - Duplicate entry found with name Member. (HTTP 409) (Request-ID: req-bfe12e47-2c06-4829-aa06-a10bd8574bde)

A workaround is to put the following into ~/.rally/rally.conf:

[openstack]
swift_operator_role = member

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/737609
Committed: https://git.openstack.org/cgit/openstack/rally-openstack/commit/?id=33dcddd41030672a88c43ca39ddb037ba6ace570
Submitter: Zuul
Branch: master

commit 33dcddd41030672a88c43ca39ddb037ba6ace570
Author: Dmitrii Shcherbakov <email address hidden>
Date: Tue Jun 23 22:30:02 2020 +0300

    Replace "Member" with "member"

    The default Keystone bootstrap process adds "member" (lowercase "m"),
    not "Member".
    https://docs.openstack.org/keystone/latest/admin/case-insensitive.html#roles

    Tempest was changed to have a lowercase default:
    https://opendev.org/openstack/tempest/commit/99d4dae684
    https://bugs.launchpad.net/tempest/+bug/1330132

    This change does the same for rally-openstack.

    Change-Id: I2b9877ac02d0d41927ff69c56e0812aa0cbbac94
    Closes-Bug: #1884825