Remove the kolla-build.conf

I got the following error when I run tox -e genconfig

tox -e genconfig
genconfig develop-inst-noop: /root/development/kolla
genconfig runtests: PYTHONHASHSEED='168146209'
genconfig runtests: commands[0] | oslo-config-generator --config-file etc/oslo-config-generator/kolla-build.conf
Traceback (most recent call last):
  File ".tox/genconfig/bin/oslo-config-generator", line 11, in <module>
    sys.exit(main())
  File "/root/development/kolla/.tox/genconfig/lib/python3.4/site-packages/oslo_config/generator.py", line 312, in main
    generate(conf)
  File "/root/development/kolla/.tox/genconfig/lib/python3.4/site-packages/oslo_config/generator.py", line 269, in generate
    for group, opts in listing:
  File "/root/development/kolla/kolla/common/config.py", line 240, in gen_all_source_opts
    for name, params in SOURCES.iteritems():
AttributeError: 'dict' object has no attribute 'iteritems'
ERROR: InvocationError: '/root/development/kolla/.tox/genconfig/bin/oslo-config-generator --config-file etc/oslo-config-generator/kolla-build.conf'

1. seem that u are using the py3, which doesn't support in the master code.
2. I had push a PS[0] to fix the py3 stuff.

[0] https://review.openstack.org/#/c/267282/

Reviewed: https://review.openstack.org/291000
Committed: https://git.openstack.org/cgit/openstack/kolla/commit/?id=3105580d39205bee6e17a2283161d18c6e7a892e
Submitter: Jenkins
Branch: master

commit 3105580d39205bee6e17a2283161d18c6e7a892e
Author: Martin André <email address hidden>
Date: Thu Mar 10 14:48:59 2016 +0900

    Provide instruction to generate kolla-build.conf

    Although not strictly mandatory, it's less confusing to have
    a kolla-build.conf file in /etc/kolla that users can modify it they
    want to customize their builds, rather than to rely on defaults
    settings and command line options.

    The `tox -e genconfig` was already documented in "Image building" doc.

    Change-Id: Ia44e6f28ce18601cdaba5109ea12cd50fa8372b2
    Closes-Bug: #1532066