Fix "log writing failed. closed stream" errors after audit phase

Currently looks like Rspec closes its streams [here](https://github.com/rspec/rspec-core/blob/master/lib/rspec/core/formatters/base_text_formatter.rb#L71) by default. This change:

* Do not close the stream on exit. 
* Include a basic framework to add basic tests we can share and hopefully automate in the future. 
* Makes it so that run doesn't fail when it gets a 404 from server when posting audit data. 

You can run the add tests under the audit_test cookbook and run them by `bundle exec chef-client -c dev-repo/dev-config.rb -z -o "audit_test" -l info`. I can remove that bit if you don't think it's really useful :smile: 

/cc: @mcquin, @tyler-ball 


We want `:audit_mode` to default to nil - if this is true it will run ONLY audits and no converges