Drop dependency on deprecated gulp-util

[TheDancingCode]

Closes #145

[pgherveou]

@TheDancingCode sorry for the late response,
Do you mind if I add you as a collaborator on this project? If you can ensure that tests pass
I would be happy to push a new version on npm.

[TheDancingCode]

I can't really collaborate on this project. I'm not an AWS user, so I can't run the tests I'm afraid. Do the tests not pass?

[demurgos]

@pgherveou
The Gulp team is in the process of creating a new organization to host popular plugins and help maintainers (gulp-community). If you're looking for collaborators, it may interest you. There is still some preparation needed but there should be more info soon.

Regarding the PR itself it should be safe to merge it (patch update from a semver point of view).

[pioug]

Tests are passing on my machine with a test bucket 👍

Though I am getting a growlnotify error related to mocha report (same error happening currently on master). I will fix that later.

I am merging and bumping. @pgherveou If you can double-check and publish on npm after 🙏

Thank everyone for your help!

[pgherveou]

Thks @pioug will do that asap