Added type hint where possible and default argument problem 234 project euler

[sondrbw]

fib has inconsistent return type so no hints added there

this fix is according to issue #2786

Describe your change:

• 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: #2786.

[TravisBuddy]

Hey @sondrewang,
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TravisCI finished with status errored, which means the build failed because of something unrelated to the tests, such as a problem with a dependency or the build process itself.

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TravisBuddy Request Identifier: c8ccb190-0a0e-11eb-b8c5-47e0b209ea74

[dhruvmanila]

For this specific solution, it's not going to be this simple. You will have to change the solution completely as it requires input from the user. So, if you're up for the challenge, go on otherwise you can close this PR.