Chore: Add HumanError as a dependency
Feature: Add the VerifiableModel module

We were duplicating a lot of logic in regards to determining whether the model
that we were showing, updating or destroying in the controllers existed.  If it
didn't, we wanted to make sure that we were throwing a `ResourceNotFoundError`
with the proper information.

This module allows us to define which resources we need to verify for which
actions.  It is used thusly:

```ruby
class MyController < ApplicationController
  verify_model_exists 'my_resource', except: %i{actions not to verify}
end
```

The information defaults to:

  * except:   %i{create index}
  * resource: The first part of the controller name
Version Bump to 0.0.4