application settings with settingslogic

Using the gem [settingslogic](https://rubygems.org/gems/settingslogic) these changes will:

* Give us a configuration file at config/newsstoryfinder.yml to do our own individual settings and keep important stuff like oauth/omniauth details out of the public repo
* NewsStoryFinder.config (which just returns Settings) that allows us to do things like `NewsStoryFinder.config.email.from` which by default would return nsf@example.com

@sandbox42 if this gets pulled in I think it would be great if we paired on Facebook/Twitter authentication as it should be a pretty straight forward simple process.