Add parameterized support for OS

This commit adds a variable operatingsystem
which can be exported to select the OS to test
the openstack deploy on.
Merge pull request #58 from pkilambi/master

fix the box_type centos check
Remove variable module_repo

Previously, the module path was prepended to the module_repo.

This was moving too much logic to the jenkins script and
also slightly confusing b/c it does not work for the openstack-installer
project.

This commit removes the variable and just prepends the moduledir.
Merge pull request #57 from bodepd/os_to_test

Add parameterized support for OS
Merge pull request #59 from bodepd/master

Remove variable module_repo
Remove cobbler from site_manifest

This commit removes the cobbler nodes from
the site manifest. They should not always be
added to the node, they should only be added
when cobbler is being managed as a part of
the build node.

Additionally, you should be able to dynamically
create nodes as a part of the cobbler node's
hiera data.
Merge pull request #60 from bodepd/master

Remove cobbler from site_manifest