Update shopify-api and koa-shopify-auth

[stevemar]

The application is littered with deprecation notices, likely from an old shopify-api version being pulled in from koa-shopify-auth. When attempting to force to the latest shopify-api version the auth broke when launching the app. Looks like the latest version of shopify-api and koa-shopify-auth have some backwards incompatible changes related to how sessions are started.

[stevemar]

Currently we're using koa-shopify-auth 4.1.2 and shopify-api 1.4.3 - when upgrading to koa-shopify-auth to 5.0.3 it bumped shopify-api to 2.1.0.

The app appeared to mostly work but there were warning/error messages that there were webhook topics that were not published, like for updating a product.