Comparisons like greaterThan very broken

There are many cases where comparisons such as greaterThan, greatherThanOrEqual, lessThan, lessThanOrEqual do not work reliably.

Works as expected (prints false):
```
const money = createMoney({amount: 1000, currency: 'USD'})
const money2 = createMoney({amount: 100, currency: 'USD'})
console.log(money.lessThanOrEqual(money2))
```

Does NOT work as expected (prints true):
```
const money = createMoney({amount: 1000, currency: 'USD'})
const money2 = createMoney({amount: 101, currency: 'USD'})
console.log(money.lessThanOrEqual(money2))
```

Another failure (prints false)
```
const money = createMoney({amount: 999, currency: 'USD'})
const money2 = createMoney({amount: 1500, currency: 'USD'})
console.log(money.lessThan(money2))
```

That something so basic isn't working in a library devoted to money calculations makes me really nervous about using it in general in a production setting. As much as the features seem nice, it seems like Dinero is under more active development.