heat-cfntools depends on argparse

[JunJie Nan]

heat-cfntools depends on argparse:
import argparse

But argparse is not listed in requirement.txt or heat_cfntools.egg-info/requires.txt.

Without this, exception will be found when running cfn-init:
Traceback (most recent call last):
  File "/usr/bin/cfn-init", line 18, in <module>
    import argparse
ImportError: No module named argparse

This is a py26 specified problem. Steps to reproduce the problem
1. .tox/py26/bin/cfn-init -h
2. check whehter exception found

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/44874

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/44874
Committed: http://github.com/openstack/heat-cfntools/commit/1a66c0c7910f1f05718cd345a4cfdb6f82d329c0
Submitter: Jenkins
Branch: master

commit 1a66c0c7910f1f05718cd345a4cfdb6f82d329c0
Author: JUN JIE NAN <email address hidden>
Date: Tue Sep 3 21:16:35 2013 +0800

    Add argparse into requirements

    Add argparse into requirements.txt and heat_cfntools.egg-info
    requires.txt

    Fixes bug #1220071

    Change-Id: I6147a8f14ac110d8dcdc1643ced5d32594322041