A new endpoint has been made available to admin users or
scope owners on ``GET /v2/dataframes``. This will allow
end users to retrieve DataFrames in the form of JSON objects
from the CloudKitty storage backend.
Documentation and unit tests are included in this commit.
Change-Id: I784da5565d040f565945fa93d86dcef11faa72f9
a81c01d6e2