remove _id and account. add username
remove registry/serializers.py
remove /users/{userId}. change /signup to /users
remove rest-framework
remove rest-framework
add some error message
add /users/{user_name}
add detail
add get_object_or_404.
add _id which is primary key
add uuid. remove error status.
remove the parameter pk of get_object_or_404. add the parameter username
of get_object_or_404.
Merge branch 'backend'
Merge /users and /users/{user_name}
add registry.urls
Merge branch 'master' of https://github.com/Rfirm/Rpack-registry
add /users and /users/{user_name}