Convert Users, Roles, WorkspaceUsers, TaskOrders to use classmethods

atst/domain/task_orders.py

@@ -1,17 +1,17 @@
 from sqlalchemy.orm.exc import NoResultFound
 
+from atst.database import db
 from atst.models.task_order import TaskOrder
 from .exceptions import NotFoundError
 
 
 class TaskOrders(object):
-    def __init__(self, db_session):
-        self.db_session = db_session
 
+    @classmethod
     def get(self, order_number):
         try:
             task_order = (
-                self.db_session.query(TaskOrder).filter_by(number=order_number).one()
+                db.session.query(TaskOrder).filter_by(number=order_number).one()
             )
         except NoResultFound:
             raise NotFoundError("task_order")