yuyang/practice @ 5753562d72df4266c5cccf2fb33ce545fe46fd2a

yu yang 483c6daea9 add relation model		il y a 1 an
..
__init__.py	1ce3d90772 create models	il y a 1 an
base.py	f26a08348e add base model	il y a 1 an
library_book.py	b177f70f81 create models	il y a 1 an
relation.py	483c6daea9 add relation model	il y a 1 an
test.py	ae8dd6b267 add test model	il y a 1 an