Schema downloading on setup

The code from setup.js, that downloads schema:

//
// Inject "babel-plugin-transform-export-extensions"
// -----------------------------------------------------------------------------
file = path.resolve('./node_modules/babel-preset-react-app/index.js');
text = fs.readFileSync(file, 'utf8');

if (!text.includes('babel-plugin-transform-export-extensions')) {
  if (text.includes('const plugins = [')) {
    text = text.replace(
      'const plugins = [',
      "const plugins = [\n  require.resolve('babel-plugin-transform-export-extensions'),"); // prettier-ignore
    fs.writeFileSync(file, text, 'utf8');
  } else {
    throw new Error(`Failed to inject babel-plugin-transform-export-extensions in ${file}.`); // prettier-ignore
  }
}

will not be working with the usual GraphQL API. Can we replace it with https://github.com/graphcool/graphql-cli (graphql get-schema) ? It requests schema directly from GrapgQL server.

Start in setup.js at the schema-download logic shown in the issue, then review the graphql-cli graphql get-schema command and its expected configuration. Replace the current approach so setup can request the schema from a standard GraphQL server, and verify that schema downloading works through the usual GraphQL API.