Fix StubRoom for react-sdk tests

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

test/test-utils.js

@@ -259,6 +259,8 @@ export function mkStubRoom(roomId = null) {
             },
         },
         setBlacklistUnverifiedDevices: sinon.stub(),
+        on: sinon.stub(),
+        removeListener: sinon.stub(),
     };
 }