fix poor use of path.resolve, and don't try to delete a root directory. signed off by @Jonahss

lib/helpers.js

@@ -110,7 +110,7 @@ async function unzipApp (zipPath, appExt) {
     await fs.rimraf(line);
   }
   // now delete any existing zip payload
-  await fs.rimraf(path.resolve(path.dirname(zipPath), '/Payload*'));
+  await fs.rimraf(path.resolve(path.dirname(zipPath), 'Payload*'));
   let output = await unzipFile(zipPath);
   let relaxedRegStr = `(?:creating|inflating|extracting): (.+${appExt})/?`;
   // in the strict regex, we check for an entry which ends with the