Extract basic request call

Create a function out of the standard request call that handles common
headers like user agent and logging.
This makes future changes easier to digest.

Change-Id: Ia25f997df64efdce27c8fb815e544922940145c3
Add a get_data function to Service Catalog

Service catalog takes as a parameter the entire token. This makes it
difficult to extract only the service catalog component without querying
the catalog version, which should be unnecessary.

Change-Id: I3ad428fcb3279e8aa607f67f58265a085ae63440
Merge "Extract basic request call"
Merge "Add a get_data function to Service Catalog"