Add simple session management using redis

tests/conftest.py

@@ -2,6 +2,7 @@ import pytest
 
 from atst.app import make_app, make_deps, make_config
 from tests.mocks import MockApiClient, MockRequestsClient
+from atst.sessions import DictSessions
 
 
 @pytest.fixture
@@ -10,6 +11,7 @@ def app():
         "authz_client": MockApiClient("authz"),
         "requests_client": MockRequestsClient("requests"),
         "authnid_client": MockApiClient("authnid"),
+        "sessions": DictSessions(),
     }
 
     config = make_config()