keystone has a missing dep on python-prettytable

# apt-cache policy keystone
keystone:
  Installed: 2012.1~e3-0ubuntu1
  Candidate: 2012.1~e3-0ubuntu1
  Version table:
 *** 2012.1~e3-0ubuntu1 0
        500 http://us.archive.ubuntu.com/ubuntu/ precise/universe amd64 Packages
        100 /var/lib/dpkg/status

# keystone-manage list_users
Traceback (most recent call last):
  File "/usr/bin/keystone-manage", line 35, in <module>
    keystone.manage2.main()
  File "/usr/lib/python2.7/dist-packages/keystone/manage2/__init__.py", line 94, in main
    module = load_module(module_name)
  File "/usr/lib/python2.7/dist-packages/keystone/manage2/__init__.py", line 32, in load_module
    module = loader.load_module(name)
  File "/usr/lib/python2.7/pkgutil.py", line 246, in load_module
    mod = imp.load_module(fullname, self.file, self.filename, self.etc)
  File "/usr/lib/python2.7/dist-packages/keystone/manage2/commands/create_credential.py", line 3, in <module>
    from keystone.manage2 import mixins
  File "/usr/lib/python2.7/dist-packages/keystone/manage2/mixins.py", line 2, in <module>
    import prettytable
ImportError: No module named prettytable

-----

This error is resolved by installing python-prettytable

# apt-get install python-prettytable
--snip--
# keystone-manage list_users
WARNING:root:Database (sqlite:////var/lib/keystone/keystone.db) is not version controlled; run `keystone-manage sync_database` or override your migrate version manually (see docs)
+----+------+-------+-------------------+---------+
| ID | Name | Email | Default Tenant ID | Enabled |
+----+------+-------+-------------------+---------+
+----+------+-------+-------------------+---------+