as_json should ignore all arguments. Add default to_json.

[ioquatix]

Follow up to #53.

def as_json(...) should accept and ignore all arguments.

We should add a default to_json -> as_json.to_json(...) too, otherwise, JSON.dump won't use it.

Types of Changes

• Bug fix.

Contribution

• I added tests for my changes.
• I tested my changes locally.
• I agree to the Developer's Certificate of Origin 1.1.