fix: panic on using map with value of aliased type

[daniel134256]

The following will panic:

type Name string

func Test() {
    v := map[string]Name{}
    faker.FakeData(&v)
}

output:

panic: reflect.Value.SetMapIndex: value of type string is not assignable to type <package-name>.Name [recovered]

resolves #166

[bxcodec]

LGTM