[Fix] Author, Publisher, Category not saved in DB

Unique Author, Publisher & Category
Rename isbn13 to isbn for BookSerializer
Fix Null Value for publisher, authors, and categories
Fix m2m, error when required=false on m2m
User Book Serializer

User update their own book through an isbn field.
isbn is a write-only field
User can request all their books.
books in this endpoint is a read-only field
owner and current_holder is a read_only field
on restore object owner and current_holder is login user
MyBook views
Require authenticated Permission for MyBookView
Github page Client
Migration Script For Comm
Initial Migration
Book Filter by categories
Merge branch 'master' of github.com:9gix/bsapi into feature/transaction
Initial Migrations