chore: modify flowconfig to fix ci fail (#450)

Summary:
Modified flowconfig since the CI was failing

Pull Request resolved: #450

Reviewed By: mondaychen

Differential Revision: D22447384

Pulled By: drarmstr

fbshipit-source-id: c9e4ab0890a298656dc9c0810478f197fca484ee

.flowconfig

@@ -27,6 +27,7 @@ module.name_mapper='ReactTestUtils' -> '<PROJECT_ROOT>/node_modules/react-dom/te
 module.name_mapper='RecoilUtils' -> '<PROJECT_ROOT>/src/RecoilUtils.js'
 module.name_mapper='Recoil_RecoilValue' -> '<PROJECT_ROOT>/src/core/Recoil_RecoilValue.js'
 module.name_mapper='Recoil_State' -> '<PROJECT_ROOT>/src/core/Recoil_State.js'
+module.name_mapper='Recoil_Graph' -> '<PROJECT_ROOT>/src/core/Recoil_Graph.js'
 module.name_mapper='gkx' -> '<PROJECT_ROOT>/src/util/Recoil_gkx.js'
 module.name_mapper='Recoil_atom' -> '<PROJECT_ROOT>/src/recoil_values/Recoil_atom.js'
 module.name_mapper='Recoil_atomFamily' -> '<PROJECT_ROOT>/src/recoil_values/Recoil_atomFamily.js'