rake spec in puppet-tripleo contain duplicate module in newton

[Xing Zhang]

Tested puppet-module using puppet-openstack_spec_helper on branch stable/newton with a Puppetfile_extras,
will report a warn info like this:

--------------------------------------------------------------------------------
| Install Modules |
--------------------------------------------------------------------------------
+ install_modules
+ '[' -e /usr/zuul-env/bin/zuul-cloner ']'
+ install_all
+ PUPPETFILE=/root/puppet-artemis/openstack/puppet-openstack-integration/Puppetfile
+ r10k puppetfile install -v
WARN -> Puppetfiles should not contain duplicate module names and will result in an error in r10k v3.x.
WARN -> Remove the duplicates of the following modules: xxx xxx xxx

Puppetfile in puppet-openstack-integration will contain modules twice:
## xxx Puppet modules

mod 'xxx',
  :git => 'xxx',
  :ref => 'stable/newton'

## xxx Puppet modules

mod 'xxx',
  :git => 'xxx',
  :ref => 'stable/newton'

Because of stable/newton already has the patch https://github.com/openstack/puppet-openstack_spec_helper/commit/1e8dc7f7a90c5e4e64d62881077a4fd074d5a592#diff-6f6de0579c067ffbbe86d72d053c65bd at Sep 2, 2016 and cherrypick from master again at
https://review.openstack.org/#/c/427778 at Feb 1, 2017

Need revert that patch to fix it.

https://github.com/openstack/puppet-openstack_spec_helper/blob/stable/newton/lib/puppet-openstack_spec_helper/rake_tasks.rb#L73

[Xing Zhang (xingzhang)]

https://review.openstack.org/#/c/490858/