Adding Conversion methods

And appeasing Hound as the conversion methods are likely to be
complicated if statements.
Augmenting Sipity::Conversions with README
Adding ezid-client

$ bundle
@WIP Adding Ezid::Client
Preliminary commit for DOI Creation
Expanding on the DOI Creation Request Job
Updating secrets
Dependency injection for DoiCreationRequest
Teasing apart DoiCreationRequestJob
Appeasing Rubocop
Adding Repository to DoiCreationRequest
Adding TODO items

[skip ci]
Adding comments

[skip ci]
Adding #permanent_uri_for_header_id
Introducing a metadata builder
Rudimentary metadata builder for DOI
Appeasing Rubocop
@WIP
Refinging DoiCreationRequest process
Stubbing out remote submission