Add Solution for Project Euler Problem 206 #2695

[PetitNigaud]

Describe your change:

I added the solution for the Project Euler problem 206 (#2695).

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms have a URL in its comments that points to Wikipedia or other similar explanation.
• If this pull request resolves one or more open issues then the commit message contains Fixes: #{$ISSUE_NO}.

[TravisBuddy]

Travis tests have failed

Hey @PetitNigaud,
Please read the following log in order to understand the failure reason.
It'll be awesome if you fix what's wrong and commit the changes.

TravisBuddy Request Identifier: 5fae0b00-0d92-11eb-9111-f326d0cb7f09

[dhruvmanila]

Announcement:

@PetitNigaud

This message is sent to all pull requests which are OPEN, NOT MERGED, not containing 'wontfix' label and contains 'Project Euler' or 'Project' or 'Euler' (case doesn't matter) in their title. If this message doesn't apply to your pull request, please ignore this.

Message:

This is to notify all the users submitting a pull request for the Project Euler solution that the README.md file has been updated with all the style requirements necessary for the directory and solution files. Please read through it and make all the necessary changes required to your submission.

[PetitNigaud]

I removed the doctest from the solution() function as it is tested by Travis. Due to the specific problem statement I do not see any other cas that could be tested introducing a parameter into the solution function.

[dhruvmanila]

There is already an open PR for this solution and currently, we are not accepting solutions to problems that already exist in this repository. Thank you for your contributoin.