Merge pull request #154 from pbitkowski/patch-1

Add Codility to Coding Practice Sites

Author: mr-mig

README.md

@@ -240,3 +240,4 @@ But knowing the stuff will help you become better! :muscle:*
 - :link: [CodeCombat](https://codecombat.com/)
 - :link: [InterviewCake](https://www.interviewcake.com/)
 - :link: [At Coder](https://atcoder.jp/)
+- :link: [Codility](https://www.codility.com/)