text: Title: import face_recognition error
  Body: * face_recognition version: 1.2.3
  * Python version: Python 3.6.3 |Anaconda, Inc.| (default, Oct 13 2017, 12:02:49) 
  * Operating System: ubuntu 16.04
  
  ### Description
  
  run face_recognition command and import face_recognition get following unkown error
  
  ### What I Did
  
  ```
  just follow the instruction install dlib, and pip install face_recognition
  ```
  
  Traceback (most recent call last):
    File "/opt/anaconda3/bin/face_recognition", line 7, in <module>
      from face_recognition.face_recognition_cli import main
    File "/opt/anaconda3/lib/python3.6/site-packages/face_recognition/__init__.py", line 7, in <module>
      from .api import load_image_file, face_locations, batch_face_locations, face_landmarks, face_encodings, compare_faces, face_distance
    File "/opt/anaconda3/lib/python3.6/site-packages/face_recognition/api.py", line 23, in <module>
      cnn_face_detector = dlib.cnn_face_detection_model_v1(cnn_face_detection_model)
  RuntimeError: Error while calling cudaGetDevice(&the_device_id) in file /tmp/pip-build-lc1rkd_0/dlib/dlib/cuda/gpu_data.cpp:201. code: 30, reason: unknown error
  