Fix schema for invoice email updating

Fixes #1209

endpoints/api/organization.py

@@ -121,7 +121,7 @@ class Organization(ApiResource):
           'description': 'Whether the organization desires to receive emails for invoices',
         },
         'invoice_email_address': {
-          'type': 'string',
+          'type': ['string', 'null'],
           'description': 'The email address at which to receive invoices',
         },
         'tag_expiration': {

endpoints/api/user.py

@@ -199,7 +199,7 @@ class User(ApiResource):
           'description': 'The user\'s username',
         },
         'invoice_email_address': {
-          'type': 'string',
+          'type': ['string', 'null'],
           'description': 'Custom email address for receiving invoices',
         }
       },

test/test_api_usage.py

@@ -46,7 +46,7 @@ from endpoints.api.organization import (OrganizationList, OrganizationMember,
                                         OrgPrivateRepositories, OrganizationMemberList,
                                         Organization, ApplicationInformation,
                                         OrganizationApplications, OrganizationApplicationResource,
-                                        OrganizationApplicationResetClientSecret)
+                                        OrganizationApplicationResetClientSecret, Organization)
 from endpoints.api.repository import RepositoryList, RepositoryVisibility, Repository
 from endpoints.api.permission import (RepositoryUserPermission, RepositoryTeamPermission,
                                       RepositoryTeamPermissionList, RepositoryUserPermissionList)
@@ -2890,6 +2890,13 @@ class TestOrganizationApplicationResource(ApiTestCase):
                          expected_code=404)
 
 
+class TestOrganization(ApiTestCase):
+  def test_change_send_billing_invoice(self):
+    self.login(ADMIN_ACCESS_USER)
+    self.putJsonResponse(Organization, params=dict(orgname=ORGANIZATION),
+                         data=dict(invoice_email=False, invoice_email_address=None))
+
+
 class TestOrganizationApplicationResetClientSecret(ApiTestCase):
   def test_reset_client_secret(self):
     self.login(ADMIN_ACCESS_USER)