Add editor and translator fields to module collection

Add two arrary strings at backend and through to API, and add tests to confirm the GET works
move from ids to names

We want to use names of some format not UUIDs in the authors and editors fields. they are for display only so not ACL supported.  I have copnverted the tests to use a known name
Merge pull request #148 from Connexions/editor-translator-fields

Editor translator fields in db