Description of problem:
When running instack-install-undercloud on a fresh RHEL 7.1 bare metal server, it fails with "ImportError: No module named six". It succeeds if you run "sudo yum install -y python-six" first.

Version-Release number of selected component (if applicable):
instack.noarch                   0.0.6.4-g57c723a.el7.centos
instack-undercloud.noarch        2.0.0-dev1662.el7.centos @delorean-rdo-management


How reproducible:
100%

Steps to Reproduce:
1. Install RHEL 7.1 on bare metal
2. Follow sphinx instructions to install instack RPMs
3. Run "instack-install-indercloud"

Actual results:
instack-install-undercloud fails when it can't find the six module.

Expected results:
The instack installation scripts should complete.

Additional info:
Output of command, starting just before the error:

+ target_tag=10-install-git
+ date +%s.%N
+ output '10-install-git completed'
++ date
+ echo puppet-tuskar Fri Apr 24 02:09:22 CEST 2015 10-install-git completed
puppet-tuskar Fri Apr 24 02:09:22 CEST 2015 10-install-git completed
+ for target in '$targets'
+ output 'Running /tmp/tmpYtenhF/extra-data.d/10-merge-svc-map-files'
++ date
+ echo puppet-tuskar Fri Apr 24 02:09:22 CEST 2015 Running /tmp/tmpYtenhF/extra-data.d/10-merge-svc-map-files
puppet-tuskar Fri Apr 24 02:09:22 CEST 2015 Running /tmp/tmpYtenhF/extra-data.d/10-merge-svc-map-files
+ target_tag=10-merge-svc-map-files
+ date +%s.%N
+ /tmp/tmpYtenhF/extra-data.d/10-merge-svc-map-files
Traceback (most recent call last):
  File "/tmp/tmpYtenhF/extra-data.d/10-merge-svc-map-files", line 18, in <module>
    import six
ImportError: No module named six
INFO: 2015-04-24 02:09:22,703 -- ############### End stdout/stderr logging ###############
ERROR: 2015-04-24 02:09:22,703 --     Hook FAILED.
ERROR: 2015-04-24 02:09:22,703 -- Failed running command ['dib-run-parts', u'/tmp/tmpYtenhF/extra-data.d']
  File "/usr/lib/python2.7/site-packages/instack/main.py", line 153, in main
    em.run()
  File "/usr/lib/python2.7/site-packages/instack/runner.py", line 79, in run
    self.run_hook(hook)
  File "/usr/lib/python2.7/site-packages/instack/runner.py", line 174, in run_hook
    raise Exception("Failed running command %s" % command)
ERROR: 2015-04-24 02:09:22,704 -- None