async function handlePostCSS(file) {
    const name = path.basename(file);
    const dest = config.css.dest;

    let res = await postcssCompiler({
        file,
        dest,
        minify: true
    }).catch(error => console.log(error));
    if (!res) {
        return false;
    }
    console.log('PostCSS Build', `Compiled and Minified ${name}`);
}
Handle Postcss files
compile the css files

@param {string} file path