Spect does not complain about non-nullable struct fields missing

[23Skidoo]

For example, given the following struct definition:

typed_struct enforce: true do
    field :foo, String.t()
end

Spect will happily accept an empty map as valid:

> Spect.to_spec(%{}, __MODULE__)
{:ok, %__MODULE__{foo: nil}}

[23Skidoo]

"Extra" fields being present also don't result in an error:

> Spect.to_spec(%{bar: "baz"}, __MODULE__)
{:ok, %__MODULE__{foo: nil}}