Not accessible fields for pair and triple types

When writing any code using `pair` or `triple` types, there's no possibility to access its fields despite them being public:
```nim
import tribalify

var i = newPair(5, 10)
echo i.first
```
I'm writing it here mostly to signify that the issue is known and worked on. I will do my best to fix it for 0.2.0, since it is one of major issues with library right now.