Sign TO in post route

atst/domain/task_orders.py

@@ -1,3 +1,4 @@
+import datetime
 from flask import current_app as app
 
 from atst.database import db
@@ -47,6 +48,16 @@ class TaskOrders(BaseDomainClass):
 
         return task_order
 
+    @classmethod
+    def sign(cls, task_order, signer_dod_id):
+        task_order.signer_dod_id = signer_dod_id
+        task_order.signed_at = datetime.datetime.now()
+
+        db.session.add(task_order)
+        db.session.commit()
+
+        return task_order
+
     @classmethod
     def create_clins(cls, task_order_id, clin_list):
         for clin_data in clin_list: