[identity][v3/roles] Types of some parameters are wrong
[identity][v3/roles] Types of some parameters are wrong

Changing type of:
- "role" from "xsd:string" to "xsd:dict"
- "roles" from "xsd:string" to "xsd:list"

Change-Id: I90b6e3d9b1f0642d539135d91f72745f996b3fd3
Closes-Bug: #1547363

Tesora/tesora-api-site,openstack/api-site,openstack/api-site,Tesora/tesora-api-site,openstack/api-site,Tesora/tesora-api-site,Tesora/tesora-api-site,openstack/api-site,Tesora/tesora-api-site,Tesora/tesora-api-site,Tesora/tesora-api-site