"1. Invalid data type for [parameter_name]" with typespec boolean().

In the create view http://localhost:8001/admin/model/create/example, are there values the form which would be accepted as the boolean atoms?

The error message doesn't give the user enough information to resolve this on their own.

src/model/example.erl:

``` erlang
-module(example, [Id, Name, Description, Notes, Enabled::boolean()]).
-compile(export_all).
```
