JSON type handling

[jeromegn]

I'm not seeing the JSON type being used in my struct fields defined as JSON in sqlite. I might be missing a setting! I can't find information on how to get them working for sqlite.

To even get JSON support with the sqlite3 driver, users need to go build with --tags "json1". Maybe that's missing from the sqlboiler generation flow?

I see there is a json field in the testdatabase.sql, but the "golden" json reference marks these fields as string and null.String (which is also what I'm seeing in my own structs).

It doesn't matter too much, but this might've been overlooked.