handful of minor tweaks.

just some minor things i noticed. also shopify-api should now catch `errors` and give back an error with `type` of `ShopifyInvalidRequestError` with a `detail` key containing the `errors` array. i will have some more tweaks in the next few weeks after i overhaul shopify-api based on some of the things i seen here including merging the asset so that you dont need assetLegacy or that whole if statement.