Wrong keystone_authtoken middleware configuration for devstack

[Mike Fedosin]

Devstack recommends to use special function "configure_auth_token_middleware" to specify the middleware parameters https://github.com/openstack-dev/devstack/blob/1ca22d50b0847f9af0c569ed32f358711952b17a/lib/keystone#L424-L448

Glare doesn't use it and it causes a misconfiguration of the middleware:
[keystone_authtoken]
identity_uri = http://104.130.222.62/identity
auth_uri = http://104.130.222.62/identity/v3
admin_password = secretservice
admin_user = glare
admin_tenant_name = service
auth_protocol = http
auth_port = 35357
auth_host = 104.130.222.62

For instance, a configuration of a glance server:
[keystone_authtoken]
memcached_servers = 104.130.222.62:11211
signing_dir = /var/cache/glance/api
cafile = /opt/stack/data/ca-bundle.pem
project_domain_name = Default
project_name = service
user_domain_name = Default
password = secretservice
username = glance
auth_url = http://104.130.222.62/identity
auth_type = password

This leads to the fact that Glare does not work with some keystone configurations and returns 503 errors from authtoken middleware.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/473631
Committed: https://git.openstack.org/cgit/openstack/glare/commit/?id=5aba8880d1fc4554ae0d9d0c5cd273dfbc43582f
Submitter: Jenkins
Branch: master

commit 5aba8880d1fc4554ae0d9d0c5cd273dfbc43582f
Author: Mike Fedosin <email address hidden>
Date: Tue Jun 13 03:48:59 2017 +0300

    Fix devstack deployment

    This patch adds two improvements in devstack shell script:

    1. Now we use uncommented yaml file for default policies.

    2. configure_auth_token_middleware function is used to setup
    keystone_authtoken middleware instead of custom implementation.

    Closes-bug: #1697686

    Change-Id: I5448486019c9ed20a4eb656d48985b5d4958848b