When loading JSON data bag files, dwim attempts to use non-existent Yaml loader

```
% knife dwim data_bags/users/nagiosadmin.json
ERROR: knife encountered an unexpected error
This may be a bug in the 'dwim' knife command or plugin
Please collect the output of this command with the `-VV` option before filing a bug report.
Exception: NameError: uninitialized constant Chef::Knife::DataBagFromYaml
```