Pass name tag to expo for use in registerRootComponent

Hi, I am using expo’s bare workflow but with expo go client. Changing IOS moduleName from main in AppDelegate.m causes the application to crash as expo uses main as the root component tag. I have to let go of the benefits of using expo go client. Would it be possible to pass the name as an argument but set main as the default in case no name is passed?

An example would be

export default function registerRootComponent(component, name='main') {
    AppRegistry.registerComponent(name, () => withExpoRoot(component));

This would ensure people working with the bare workflow can enjoy the benefits of the expo go client when they need to even in a bare workflow.

I can create a pull request if need be.

Thank you. :slightly_smiling_face: