Add way to disable ok logging

[cjm771]

i prefer grunt logs to only output errors vs all info, would be possible to add options.logging = ["warn"', "error"] to the options to have it ignore "ok" writing for this specific task? thanks!

[C-Lodder]

Hi @cjm771, I won't be adding any features into this package. The only reason I forked it was to allow developers to keep using it with more recent PostCSS versions.