Changed db queries to use one, which throws NoResultFound exception, this exception is dealt with in our error handlers.

Now a lot of the if none checks can be removed.

tests/app/dao/test_services_dao.py

@@ -11,7 +11,7 @@ from app.dao.services_dao import (
 )
 from app.dao.users_dao import save_model_user
 from app.models import Service, User
-from sqlalchemy.orm.exc import FlushError
+from sqlalchemy.orm.exc import FlushError, NoResultFound
 from sqlalchemy.exc import IntegrityError
 
 
@@ -145,7 +145,9 @@ def test_get_all_user_services_should_return_empty_list_if_no_services_for_user(
 
 
 def test_get_service_by_id_returns_none_if_no_service(notify_db):
-    assert not dao_fetch_service_by_id(str(uuid.uuid4()))
+    with pytest.raises(NoResultFound) as e:
+        dao_fetch_service_by_id(str(uuid.uuid4()))
+    assert 'No row was found for one()' in str(e)
 
 
 def test_get_service_by_id_returns_service(service_factory):