Bump minor version to 0.7.0

Revert JSON-only content type changes

Make Content-Type JSON for all requests

Add support for the Marketplace Reviews and Assortment Recommendations APIs

Update existing APIs from upstream

Update Walmart class to support multiple hosts

Add schema deletions file

Relocate models and schema modification files

Fix API key retrieval and signature generation

Bump patch version to 0.6.3

Fix Walmart::supplier() return type, remove Walmart::warehouseSupplier() and Walmart::dropShipVendor()

Fix Prices API access in MarketplaceApi.php

Bump patch version to 0.6.2

Add Contributing section to README

Merge pull request #8 from friendscottn/main