Localize notification_utils to the admin

This changeset pulls in all of the notification_utils code directly into the admin and removes it as an external dependency. We are doing this to cut down on operational maintenance of the project and will begin removing parts of it no longer needed for the admin.

Signed-off-by: Carlo Costino <carlo.costino@gsa.gov>

tests/notifications_utils/conftest.py

@@ -0,0 +1,45 @@
+import pytest
+import requests_mock
+from flask import Flask
+
+from notifications_utils import request_helper
+
+
+class FakeService:
+    id = "1234"
+
+
+@pytest.fixture
+def app():
+    flask_app = Flask(__name__)
+    ctx = flask_app.app_context()
+    ctx.push()
+
+    yield flask_app
+
+    ctx.pop()
+
+
+@pytest.fixture
+def celery_app(mocker):
+    app = Flask(__name__)
+    app.config["CELERY"] = {"broker_url": "foo"}
+    app.config["NOTIFY_TRACE_ID_HEADER"] = "Ex-Notify-Request-Id"
+    request_helper.init_app(app)
+
+    ctx = app.app_context()
+    ctx.push()
+
+    yield app
+    ctx.pop()
+
+
+@pytest.fixture(scope="session")
+def sample_service():
+    return FakeService()
+
+
+@pytest.fixture
+def rmock():
+    with requests_mock.mock() as rmock:
+        yield rmock