e12b1_most_repeated_vowels.py gives IndexError if word has no vowels

My suggestion:


```python
def most_repeating_vowel_count(word):
    vowels = 'aieouAIEOU'
    vowel_dict = Counter({letter: count for letter, count in Counter(word).items() if letter in vowels})
    if not vowel_dict:  # if there are no vowels in the word
        return 0
    else:
        return vowel_dict.most_common(1)[0][1]
```