Collect response headers and method to check current limit

Thanks to @RRStoyanov, now this package is capable of checking the current api limit:

• Collect response headers while taking user by token
• Add method to check current api limit based on collected headers

Example usage for default apps should be something like this:

if ($shopify->getShopifyAuth()->checkCurrentApiLimit() > 39) {
    sleep(1);
}

Fixed the nested array issue

Thanks to @RRStoyanov , error {"metafields":"expected Hash to be a Array"} has been fixed!

CRUD requests from API call

1.0.3

Create README.md

Billing Support

• Added support for billing;
• Uses stateless OAuth authentication

1.0.0

initial