new icon: gitkraken (original, original-wordmark, plain, plain-wordmark)

[boterop]

Double check these details before you open a PR

• PR does not match another non-stale PR currently opened
• PR name matches the format new icon: Icon name (versions separated by comma). More details here
• PR's base is the develop branch.
• Your icons are inside a folder as seen here
• SVG matches the standards laid out here
• A new object is added in the devicon.json file at the correct alphabetic position as seen here

This PR closes #1455

Link to prove your SVG is correct and up-to-date.

https://www.gitkraken.com/

[github-actions]

Hi!

I'm the check-bot and we have some issues with your PR:

devicon.json is not sorted correctly.
Please make sure that your icon is added in the `devicon.json` file at the correct alphabetic position
as seen here: https://github.com/devicons/devicon/wiki/Updating-%60devicon.json%60

Check our CONTRIBUTING guide for more details regarding these errors.

Please address these issues. When you update this PR, I will check your SVGs again.

Thanks for your help,
SVG-Checker Bot 😄

[github-actions]

Hi!

I'm the check-bot and we have some issues with your PR:

devicon.json is not sorted correctly.
Please make sure that your icon is added in the `devicon.json` file at the correct alphabetic position
as seen here: https://github.com/devicons/devicon/wiki/Updating-%60devicon.json%60

Check our CONTRIBUTING guide for more details regarding these errors.

Please address these issues. When you update this PR, I will check your SVGs again.

Thanks for your help,
SVG-Checker Bot 😄

[canaleal]

Great work! 💯

I optimized the SVGs using SVGOMG and checked them with IcoMoon for any artifacts.

Additionally, since the original SVG contains only one path and fill color, it can also serve as an alias for the plain SVG.

[weh]

Just some minor changes, the rest looks good 👍