Improve Twitter icon
Improve Twitter icon

Current Twitter icon is rather crispy [1], so I changed the code to version from jekyll/minima project [2].

Note: it is a little bit smaller (which is unnoticeable without direct comparison [3]), so if it is not OK, feel free to close this pull request and change it yourself.

[1]: https://pbs.twimg.com/media/DJyGJWhXcAEPH0r.jpg
[2]: https://github.com/jekyll/minima/blob/master/_includes/icon-twitter.svg
[3]: https://i.imgur.com/PWa8h8r.gifv
ilyabirman/Likely,ilyabirman/Likely