input: Write a python function to find the most common fruit in a list.
  assert most_common_fruit(["apple", "banana", "apple", "orange", "banana", "apple"]) == "apple"
  assert most_common_fruit(["pear", "pear", "banana", "banana", "pear", "banana"]) == "pear"
  assert most_common_fruit(["grape", "grape", "grape", "orange", "orange", "orange", "grape"]) == "grape"
output: def most_common_fruit(fruits):
      from collections import Counter
      count = Counter(fruits)
      return count.most_common(1)[0][0]