Error if frames folder doesn't exist

[abid-mujtaba]

Running the tool in a location where the frames/ sub-folder doesn't already exists results in the following error:

[Error: ENOENT: no such file or directory, stat './/frames'] {
  errno: -2,
  code: 'ENOENT',
  syscall: 'stat',
  path: './/frames'
}

This is probably caused by the fs.rmdir call on this line. The likely fix is to first check for existence before the folder is removed.