copy: wrap `copy-paste` and make it `await`-friendly

lib/copy.js

@@ -0,0 +1,10 @@
+import { copy as _copy } from 'copy-paste';
+
+export default function copy (text) {
+  return new Promise((resolve, reject) => {
+    _copy(text, (err) => {
+      if (err) return reject(err);
+      resolve();
+    });
+  });
+}