yolov3

Defaulting to user installation because normal site-packages is not writeable
Collecting yolov3
Using cached yolov3-1.7-py3-none-any.whl (1.5 kB)
Collecting numpy==1.14.4 (from yolov3)
Using cached numpy-1.14.4.zip (4.9 MB)
Preparing metadata (setup.py) ... done
INFO: pip is looking at multiple versions of yolov3 to determine which version is compatible with other requirements. This could take a while.
Collecting yolov3
Using cached yolov3-1.6-py3-none-any.whl (1.5 kB)
Using cached yolov3-1.5-py3-none-any.whl (1.5 kB)
Using cached yolov3-1.4-py3-none-any.whl (1.5 kB)
Using cached yolov3-1.3-py3-none-any.whl (1.5 kB)
Using cached yolov3-1.2-py3-none-any.whl (1.5 kB)
Using cached yolov3-1.1.0-py3-none-any.whl (1.5 kB)
Using cached yolov3-1.0-py3-none-any.whl (1.5 kB)
INFO: pip is still looking at multiple versions of yolov3 to determine which version is compatible with other requirements. This could take a while.
ERROR: Cannot install yolov3==1.0, yolov3==1.1.0, yolov3==1.2, yolov3==1.3, yolov3==1.4, yolov3==1.5, yolov3==1.6 and yolov3==1.7 because these package versions have conflicting dependencies.

というエラーが出ます。解決方法を教えて下さい。