Currently we use Ansible 2.2 in kolla_toolbox, while lowest supported
version is 2.6 - bumping up to 2.8.
* Use upper constrains in Dockerfile.j2, instead of pinning them in
here - Ansible is pinned to 2.8.*
* Add no_log=True in kolla_keystone_user
* Add endpoint_type as a param in kolla_keystone_service - now
AnsibleModule requires all options to be defined, otherwise it throws
an UnsupportedParameter error
* Add openstack_release variable in kolla/common/config.py which
is used for fetching upper-constraints.txt for desired release
Change-Id: I2cb0ea2fde1b408d48b39bf7a54b898e850d31aa