Remove gutil dependency

[idleberg]

As advised by the Gulp maintainers, this PR removes the dependency on gulp-util. However, since there are no type declarations for two of the replacement modules, errors are thrown during build. How should these be handled?

[demurgos]

This is tracked with this gulp-tslint issue and this gulp-util issue.

Instead of ansi-*, it's better to use chalk which bundles type definitions. Type definitions for plugin-error got merged recently. Thank you for your help, but as stated in the issue, there is already a PR ready to be made, we're just waiting for the next version of plugin-error to be released: it should come soon.

A patch was submitted for vinyl-fs to keep the current version of gulp-util working with Gulp 4 so this is less urgent.

Besides, it's better to fix the issues one by one: I don't think this PR should upgrade to Gulp 4 (it's better to have a separate PR).

[panuhorsmalahti]

Agree with @demurgos

[gucong3000]

Should use fancyLog.error ?

[idleberg]

@gucong3000 As far as I understand, #6 already takes care of all necessary changes. Anyway, since my fork was still lying around I made the adjustments, should anybody still want them.

[demurgos]

@idleberg
I don't see the relation with #6, is it a typo? The changes were discussed in #140 but blocked by plugin-error. They just released their new version so it allowed #143 to be submitted (it should supersede this PR).

Side note: I still think that the Gulp 4 update is outside of the scope of this PR.