apollo-scalajs-core example is missing a 'fetcher' to run

[NicolasRouquette]

I made a reproducible example of several problems I experienced with apollo-scalajs-core version 0.5.0. https://github.com/NicolasRouquette/apollo-scalajs-core-example

See the README for problems with the doc. To reproduce the problem with a missing 'fetcher', run: sbt run

[shadaj]

Hi @NicolasRouquette, you should be able to pass in the fetch implementation you want to use when constructing ApolloClient. The idea is that the fetcher is unspecified to allow users to either use a built-in fetch or one from a polyfill based on the application.