Non-object record types are converted to objects

[OliverJAsh]

import { ofType, unionize, UnionOf } from 'unionize';

const MyUnion = unionize({
    MyVariant: ofType<string[]>(),
});
type MyUnion = UnionOf<typeof MyUnion>;

MyUnion.match({
    MyVariant: strs => strs.map(x => x), // runtime error!
});

Related: #67

Workaround: specify a value:

 const MyUnion = unionize({
     MyVariant: ofType<string[]>(),
-});
+}, { value: 'value' });