Some fixes and updates over the past month

Amazon
: Added support for an improved and more efficient syncing method
Bandcamp
: Added support for the new partner system
BigCommerce
: Improved syncing and listing refreshing
Shopify
: Fixed an issue that prevented overdue subscriptions from being properly determined
Google Shopping
: Added support to listings without images
Fixed an issue that prevented subscriptions from being updated if the charge failed
Some other internal adjustments and fixes to keep Trunk working like a charm!