decode-nested-array-values

I'm trying to use `tnetstring-go` to encode/decode a structure like:

```javascript
{
  "id":        "string-uuid",
  "method":    "get",
  "uri":       "http://example.com
  "headers":   [["name1", "value1"], ["name2", "value2"]],
  "body":      "body-string"
  "user-data": {"more": "keys",
                "and" : "values"}
}
```

I'm still groking the code to figure out what the issue is, but in the
meantime I have a failing test case.