SCRD-3484 Use keystoneclient for endpoint retrieval
SCRD-3484 Use keystoneclient for endpoint retrieval

Use keystoneclient functions for getting endpoints and services instead
of using the low-level get() interface on the session object.  This is
the correct interface to use with keystone, and it lets the
keystoneclient library take care of converting the payload into python
objects and so on.

Change-Id: I36f784cd05f9433bd4c9c6ead5d8ddb752cb1fde

ArdanaCLM/ardana-service,ArdanaCLM/ardana-service