update docs and templates to use tenant IDs (instead of names)

As keystone now uses tenant IDs internally we should update docs, examples, and templates to use IDs instead of names for tenants.

For example. Instead of:

curl -d '{"passwordCredentials": {"username": "joeuser", "password": "secrete", "tenantId": "1234"}}' -H "Content-type: application/json" http://localhost:5000/v2.0/tokens

We should now use:

curl -d '{"passwordCredentials": {"username": "joeuser", "password": "secrete", "tenantId": "1"}}' -H "Content-type: application/json" http://localhost:5000/v2.0/tokens

** NOTE: using 1234 as a sample tenant name is probably bad since 1234 is really the name of the tenant although it also could be the ID.