Add support for parsing and exposing isbn types (!18) · Merge requests · crossref / REST API

Mark Woodhall requested to merge isbn-type into master Mar 24, 2018

This pull request adds support for parsing ISBN types and follows the pattern that already exists for ISSN types.

It also enables storing and exposing book edition numbers and part numbers via the API.

This is required for CrossRef/rest-api-doc#341 & CrossRef/rest-api-doc#342

Add support for parsing and exposing isbn types