use chalk for stderr colors

lib/error.js

@@ -1,4 +1,5 @@
 import ms from 'ms';
+import chalk from 'chalk';
 
 export function handleError (err) {
   if (403 === err.status) {
@@ -20,6 +21,6 @@ export function handleError (err) {
   }
 }
 
-export function error (err) {
+export function error (msg) {
-  console.error(`> \u001b[31mError!\u001b[39m ${err}`);
+  console.error(`> ${chalk.red('Error')} ${msg}`);
 }