add attachment model and task order relation to it

tests/conftest.py

@@ -3,25 +3,34 @@ import pytest
 import alembic.config
 import alembic.command
 from logging.config import dictConfig
+from werkzeug.datastructures import FileStorage
+from tempfile import TemporaryDirectory
 
 from atst.app import make_app, make_config
 from atst.database import db as _db
 import tests.factories as factories
+from tests.mocks import PDF_FILENAME
 
 dictConfig({"version": 1, "handlers": {"wsgi": {"class": "logging.NullHandler"}}})
 
 
 @pytest.fixture(scope="session")
 def app(request):
+    upload_dir = TemporaryDirectory()
+
     config = make_config()
+    config.update({"STORAGE_CONTAINER": upload_dir.name})
 
     _app = make_app(config)
 
     ctx = _app.app_context()
     ctx.push()
 
+
     yield _app
 
+    upload_dir.cleanup()
+
     ctx.pop()
 
 
@@ -103,3 +112,9 @@ def user_session(monkeypatch, session):
         )
 
     return set_user_session
+
+
+@pytest.fixture
+def pdf_upload():
+    with open(PDF_FILENAME, "rb") as fp:
+        yield FileStorage(fp, content_type="application/pdf")