Shopifyapi

- Added support for GraphQL queries with a GraphQL resource

- Fixing missing class variable causing exception when creating a session without a token

- Added support for Shopify API Versioning

- Added AccessScope resource
- Added ApiPermission resource
- Added User resource
- Added Publication, CollectionPublication and ProductPublication resources
- Added Currency resource
- Added TenderTransaction resource
- Added shopify.Limits class, for retrieving the current status of Shopify rate limiting.
- Added support for Refund.calculate
- Added support for Location.inventory_levels
- Added support for PriceRule batch operations
- Removed `cancel()` method for RecurringApplicationCharge resource (use `destroy()` going forward)
- Fix for handling array query parameters (e.g. `foo[]=1&foo[]=2`) during HMAC calculation
- Fixed Python 3 compatibility with the API console

- Adds InventoryItem resource
- Adds InventoryLevel resource
- Adds GiftCardAdjustment resource
- Fix to properly handle byte data for Asset.attach()

- Added CollectListing resource
- Added ResourceFeedback resource
- Added StorefrontAccessToken resource
- Added ProductListing resource
- Removed deprecated ProductSearchEngine resource
- Removed deprecated Discount resource
- Fixed Python3 compatibility issue with `Image.attach_image()`