Revert "Add request/access token and consumer..."

This reverts commit 2e7bdb872e9660178451f71b35976a980f047300.

This commit I9137e3426c82c73855ae0e50317cfd6477195318 is the second
patch that broke stable/havana by introducing a dependency on oauthlib,
but oauthlib isn't in the stable/havana branch of global dependencies
(fix in progress Ib2e2aa2e75e7b7b43e0534eeb62e748d1edc0bc3). And we use
trunk clients in stable/havana gate jobs. So this patch broke both heat
and horizon, both of which import this file to support keystone's v3 API.

This is the final patch in reverting bp add-oauth-support.

Commit subject was (but exceeds maximum pep8 subject length):
Revert "Add request/access token and consumer support for keystoneclient"

Fixes-Bug: #1292797

Change-Id: Ib45fb39b01ddcf5c8fc0179811efded84c0cb908