Feature: Support Date types for Avro

[chuck-alt-delete]

Is your feature request related to a problem? Please describe.

Right now, if you use faker methods that generate something of type Date, it shows up as an empty record.

Describe the solution you'd like

We can implement a hook like this:

• mtth/avsc#324 (comment)

[chuck-alt-delete]

The problem with the above is we would have to do something weird to make sure Date objects actually get serialized in the way we want. It's much easier to just cast Data objects as ISO strings when they are generated. See PR