text: Title: A mistake in guidline of  Validate on LFW
  Body: Hi, 
  I am trying to follow the tutorial of Validate on LFW. However I found an error in the command. I think that it may be confused the beginner. I help to address the mistake.
  ```
  cd ~/datasets  
  mkdir -p lfw/raw  
  tar xvf  ~/Downloads/lfw.tgz -C /lfw/raw --strip-components=1
  ```
  
  While we are in the `~/datasets` folder, we need to decompress the files into `lfw/raw` rather than `/lfw/raw`.
  Thanks!