Stop configure 'member' role in tempest_roles

Config option auth.tempest_roles is used to set the
extra roles to all dynamic cred tests users.
- https://opendev.org/openstack/tempest/src/commit/9b6f441fdc2a970410ea631dc1318896349e010f/tempest/common/credentials_factory.py#L82

Devstack set the 'member' role in CONF.auth.tempest_roles
- https://opendev.org/openstack/devstack/src/commit/556f84aea90c572873fc9834292635b41e590224/lib/tempest#L628

This cause issue if any tests testing for speciifc rols and want
to exclude the 'member' role, basically this bug
- https://bugs.launchpad.net/devstack/+bug/1915740

Also with 'member' role assigned by default, Tempest will not be
able to test the secure RBAC new default 'reader' role.

Let's remove  this role assignment now and let test congfigure what
they want.

Closes-Bug: #1915740

Change-Id: I0b6ab9fb943c7b0925a0a0d2490a8bcdfa76cedc
1 file changed