proof dies if a 'type' is not specified for a config option

If a config.yaml option does not have a 'type' charm-proof cannot handle it and throws an exception, exiting ungracefully.

[bac]bac@trusty64:~/charms/precise$ bzr get lp:~springfield-team/charms/precise/nova-cloud-controller/trunk nova-cloud-controller
Branched 78 revisions.

[bac]bac@trusty64:~/charms/precise$ charm-proof nova-cloud-controller/
Traceback (most recent call last):
  File "/usr/bin/charm-proof", line 9, in <module>
    load_entry_point('charm-tools==1.2.10', 'console_scripts', 'charm-proof')()
  File "/usr/lib/python2.7/dist-packages/charmtools/proof.py", line 63, in main
    args.debug)
  File "/usr/lib/python2.7/dist-packages/charmtools/proof.py", line 56, in proof
    lint, err_code = c.proof(with_remote)
  File "/usr/lib/python2.7/dist-packages/charmtools/charms.py", line 412, in proof
    lint.check_config_file(charm_path)
  File "/usr/lib/python2.7/dist-packages/charmtools/charms.py", line 185, in check_config_file
    expected_type = KNOWN_OPTION_TYPES[option_value['type']]
KeyError: 'type'