Adding explicit require for sipity/jobs

For some reason specs fail when I use the following command

```console
$ rspec --pattern ./spec/jobs/\*\*/\*_spec.rb
```
Adding spec for DoiCreationRequest defaults
Adding spec and reasoning for Sipity::Models
Moving Policy questions to Sipity::Policies
Extracting method to more appropriate location

The authorization layer is responsible for negotiating between the
context (controller) and the policy layer; As such I want to tease
apart that boundary and make it more decoupled.