text: Title: Train model with more than 1 image per person
  Body: * face_recognition version: 1.2.3
  * Python version: 2.7.15
  * Operating System: Windows 10
  
  ### Description
  
  I Would like to train the model with more than 1 image per each person to achieve better recognition results. Is it possible?
  
  One more question is what does [0] mean here:
  ```
  known_face_encoding_user = face_recognition.face_encodings('image.jpg')[0]
  ```
  If I put [1] here I receive "IndexError: list index out of range" error.
  