matrix.py: adds parameter to init function

[danishprakash]

adds a parameter to init method making it easier for users to understand the problem.

Fixes #572

[ilya-khadykin]

Thanks

I left a comment for discussion

[ilya-khadykin]

I think matrix is somewhat confusing name, since it just a string of numbers divided by newlines.
So, it would be more appropriate to name it as matrix_string or something else.

What do you think?

[danishprakash]

True, made the required change.

[ilya-khadykin]

Thanks, @prakashdanish and congrats on your first contribution to the repo!

Please note that there are some special 'closing issue' keywords that you can put in description of your PR and Github will take care of closing the corresponding issue automatically after merge.
It makes our work much easier. I hope this hint will help you to make your future PRs a bit better

It's a good practice to squash your commits https://github.com/exercism/docs/blob/master/contributing/git-basics.md#squashing. It isn't a big deal since I can do it myself, but it would be awesome to just click on 'Merge pull request' button 😃

Just for future reference a guide of how to write good commit messages - https://chris.beams.io/posts/git-commit/#seven-rules

[danishprakash]

@m-a-ge Did you mean, I should've written something like matrix.py: fixes #572 in the shortlog or the body?
Will take care of squashing, thanks.

[ilya-khadykin]

@prakashdanish yes, the full list of words: "close, closes, closed, fix, fixes, fixed, resolve, resolves, resolved" followed by #issue_number. I prefer to put it in PR description rather than in commit message because it's easier that way to open respective issue if needed