dtool verify results in stack trace when run on a http dataset

[tjelvar-olsson]

dtool verify http://bit.ly/simulated-lambda-reads

Results in:

Traceback (most recent call last):
  File "/Users/olssont/envs/dtool/bin/dtool", line 11, in <module>
    sys.exit(dtool())
  File "/Users/olssont/envs/dtool/lib/python2.7/site-packages/click/core.py", line 722, in __call__
    return self.main(*args, **kwargs)
  File "/Users/olssont/envs/dtool/lib/python2.7/site-packages/click/core.py", line 697, in main
    rv = self.invoke(ctx)
  File "/Users/olssont/envs/dtool/lib/python2.7/site-packages/click/core.py", line 1064, in invoke
    sub_ctx = cmd.make_context(cmd_name, args, parent=ctx)
  File "/Users/olssont/envs/dtool/lib/python2.7/site-packages/click/core.py", line 621, in make_context
    self.parse_args(ctx, args)
  File "/Users/olssont/envs/dtool/lib/python2.7/site-packages/click/core.py", line 880, in parse_args
    value, args = param.handle_parse_result(ctx, opts, args)
  File "/Users/olssont/envs/dtool/lib/python2.7/site-packages/click/core.py", line 1404, in handle_parse_result
    self.callback, ctx, self, value)
  File "/Users/olssont/envs/dtool/lib/python2.7/site-packages/click/core.py", line 78, in invoke_param_callback
    return callback(ctx, param, value)
  File "/Users/olssont/envs/dtool/lib/python2.7/site-packages/dtool_cli/cli.py", line 57, in dataset_uri_validation
    value = base_dataset_uri_validation(ctx, param, value)
  File "/Users/olssont/envs/dtool/lib/python2.7/site-packages/dtool_cli/cli.py", line 35, in base_dataset_uri_validation
    if not dtoolcore._is_dataset(value, config_path=CONFIG_PATH):
  File "/Users/olssont/envs/dtool/lib/python2.7/site-packages/dtoolcore/__init__.py", line 46, in _is_dataset
    storage_broker = _get_storage_broker(uri, config_path)
  File "/Users/olssont/envs/dtool/lib/python2.7/site-packages/dtoolcore/__init__.py", line 32, in _get_storage_broker
    return StorageBroker(uri, config_path)
  File "/Users/olssont/envs/dtool/lib/python2.7/site-packages/dtool_http/storagebroker.py", line 44, in __init__
    http_manifest_url
  File "/Users/olssont/envs/dtool/lib/python2.7/site-packages/dtool_http/storagebroker.py", line 78, in _get_json_from_url
    text = self._get_text_from_url(url)
  File "/Users/olssont/envs/dtool/lib/python2.7/site-packages/dtool_http/storagebroker.py", line 73, in _get_text_from_url
    r = self._get_request(url)
  File "/Users/olssont/envs/dtool/lib/python2.7/site-packages/dtool_http/storagebroker.py", line 67, in _get_request
    raise(HTTPError(r.status_code))
dtool_http.storagebroker.HTTPError: 404