Add Mailer class method to email TOs to MSFT

tests/conftest.py

@@ -164,6 +164,12 @@ def pdf_upload2():
         yield FileStorage(fp, content_type="application/pdf")
 
 
+@pytest.fixture
+def downloaded_task_order():
+    with open(PDF_FILENAME, "rb") as fp:
+        yield {"name": "mock.pdf", "content": fp.read()}
+
+
 @pytest.fixture
 def extended_financial_verification_data(pdf_upload):
     return {