Hijri isSameMonth incorrect

`isSameMonth` method returns true even if two dates aren't in the same Hijri month
```js
const date1 = hijri.date("10/06/2020");
const date2 = hijri.addHours(date1, 13 * 24);

date1.format("iYYYY/iM/iD") // 1442/2/19
date2.format("iYYYY/iM/iD") // 1442/3/2
hijri.isSameMonth(date1, date2) // true (it should return false)
```

Here is a link to reproduce the issue: [link](https://codesandbox.io/s/jolly-robinson-dsyi3?file=/src/index.js:111-112)