Delete openstack.common.config module

[Hiroaki Kobayashi]

openstack.common.config should be deleted because it has been replaced with oslo.config.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/422969
Committed: https://git.openstack.org/cgit/openstack/blazar/commit/?id=65c7de0abad89f41d970346399cdc6e3db8fb043
Submitter: Jenkins
Branch: master

commit 65c7de0abad89f41d970346399cdc6e3db8fb043
Author: Hiroaki Kobayashi <email address hidden>
Date: Fri Jan 20 10:53:36 2017 +0900

    Use oslo-config-generator

    This commit replaces the old configuration file generator from the
    openstack.common.config module by oslo-config-generator [1]. It also
    deletes files under tools/config which are now unused. New files are
    added for the generator:

      - climate/opts.py is for collecting climate options
      - etc/climate/climate-config-generator.conf contains generator configs
      - etc/climate/README-climate.conf.txt describes how to generate a
        sample configuration file

    In addition, a testenv:genconfig section is added to tox.ini and
    settings for the oslo.config.opts entry point are added in setup.cfg.

    [1] http://docs.openstack.org/developer/oslo.config/generator.html

    Change-Id: Ifd352dee176310fd667d1523a85afd3ddf9ab5da
    Closes-Bug: #1658908