input: Write a function to find frequency table using collections.Counter.
  assert freq_table([1, 2, 2, 3, 3, 3]) == {1: 1, 2: 2, 3: 3}
  assert freq_table(['apple', 'banana', 'apple', 'orange', 'banana', 'banana']) == {'apple': 2, 'banana': 3, 'orange': 1}
  assert freq_table([10, 20, 20, 30, 30, 30, 40, 50, 50]) == {10: 1, 20: 2, 30: 3, 40: 1, 50: 2}
output: from collections import Counter
  
  def freq_table(lst):
      return dict(Counter(lst))