
Implement a function called `hasChar()`, which checks if a string contains a letter in the specified case. The function takes two parameters:

* A string
* A letter to be found

Call example:

```php
<?php

hasChar('Hexlet', 'H'); // true
hasChar('Hexlet', 'h'); // false
hasChar('Awesomeness', 'm'); // true
hasChar('Awesomeness', 'd'); // false
```
