Fix/1271/tests new version create
Targets: #1271 (closed)
Changes proposed
This MR does a few things:
- Adds a new test case -
fails to create a book with an existing version
to test that when we request to create a new book version with existingfunded_content_type
+version
it should throw a validation error. - Added some fixes to the new version and book model that were spotted with test cases