Rename python-openstacksdk to openstacksdk
Rename python-openstacksdk to openstacksdk

The git repo is being renamed today, so we should update this doc
string. Also, correct the description. SDK is a single library, not a
collection of libraries.

Co-Authored-By: Dirk Mueller <a00b27378a09822d5638cdfb8c2e7ccc36d74c56@dmllr.de>
Change-Id: I157d3d4ce52b22e5a3f675bccb6d540e1fd2abb1

openstack/rpm-packaging,openstack/rpm-packaging