Adding Python Solution of Making Anagram

Adding Python Solution for Hackerrank question: Making Anagram

Link: https://www.hackerrank.com/challenges/ctci-making-anagrams/problem?h_l=interview&playlist_slugs%5B%5D=interview-preparation-kit&playlist_slugs%5B%5D=strings

PR: #9 
@rahulbordoloi please consider this for Hactoberfest2021.