Support flow type without configuration

[michalkvasnicak]

I want to typecheck using flow in my project but it isn't working without configuration because there is no apollo.umd.js.flow file.

As in apollographql/graphql-tag#98, copying index.js.flow to apollo.umd.js.flow should do the job just fine.

[michalkvasnicak]

Actually I tried copy the file and it does not work just as is.

[michalkvasnicak]

Ok so after investigation. index.flow.js shouldn't be in lib-def format because then you have to install it using flow-typed or point to it in .flowconfig. Also importing types from other lib-defs does not work now in flow.

Next thing is to use RequestOptions type from flow definitions instead of RequestInit from fetch lib.

And last thing is install lib defs using flow-typed and import Middleware from redux.