Cosmiconfig is not a function - babel-plugin-relay

`cosmiconfig` is capped at version 5, and conflicts with other packages using higher versions (mainly postcss and storybook).
Adding an higher resolution in my package.json breaks the plugin, because cosmiconfig > 6 dropped default exports. Would you be willing to accept a PR fixing this?

Start with package.json and the babel-plugin-relay package to trace how cosmiconfig is imported and resolved. Reproduce the failure with cosmiconfig above version 6 alongside the conflicting dependencies, then verify that the plugin loads successfully under the supported resolution.

Written by the indexing model from the issue text.