Replace chalk with gulp-util.color

[stephenlacy]

gulp-util has an instance of chalk built in.
Removing require('chalk'), and replacing chalk.blue with gutil.colors.blue will keep it even with gulp's plugin style.

[sindresorhus]

lol, you don't realize, but gulp-util is using chalk ;)

I'm just being explicit as gulp-util is just a temporary measure to keep plugins adhering to our guidelines.

[stephenlacy]

Yes, I know it is using chalk. That is Why I opened this.

[RehanSaeed]

gulp-util is being deprecated.