Properly encoded request data to conform with application/json conten…

[tyrone-digitalcake]

Graphql client content-type bug fix

WHY are these changes introduced?

Fixes #385 #385

Using the Graphql client to make a request with only the query as request data resulted into a 400 "Bad Request" error due to the application/graphql content-type header being removed.

WHAT is this pull request doing?

This request json encodes the request body also if the $data variable is not a string in Shopify\Clients\Graphql::query();

Before

After

Type of change

• Patch: Bug (non-breaking change which fixes an issue)
• Minor: New feature (non-breaking change which adds functionality)
• Major: Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• [] I have added a changelog entry, prefixed by the type of change noted above
• [] I have added/updated tests for this change
• [] I have updated the documentation for public APIs from the library (if applicable)

[tyrone-digitalcake]

I have signed the CLA!

[lizkenyon]

Thank you very much for this fix. Releasing right away.

[lizkenyon]

Some testes needed to be updated to a copied your change into #387 . I have released the fix.

[tyrone-digitalcake]

My apologies for the tests, I’ll add them if I make a pull request in future.

Thank you for releasing