Add solution for Project Euler problem 91. (#3144)

* Added solution for Project Euler problem 91. Reference: #2695

* Added doctest for solution() in project_euler/problem_91/sol1.py

* Update docstring and 0-padding in directory name. Reference: #3256

* Update sol1.py

Co-authored-by: Dhruv <dhruvmanila@gmail.com>

fpringle committed 5y ago

b74f3a8b4885b99a48ddb3ab654bc2883f97721a

Parent: b96e6c7

Committed by GitHub <noreply@github.com> on 10/16/2020, 10:14:06 AM