Use conda torchvision version

[yf225]

This tries to fix the following error on current master:

May 23 16:18:47 Traceback (most recent call last):
May 23 16:18:47   File "main.py", line 7, in <module>
May 23 16:18:47     from torchvision import datasets, transforms
May 23 16:18:47   File "/opt/conda/lib/python3.6/site-packages/torchvision/__init__.py", line 1, in <module>
May 23 16:18:47     from torchvision import models
May 23 16:18:47   File "/opt/conda/lib/python3.6/site-packages/torchvision/models/__init__.py", line 11, in <module>
May 23 16:18:47     from . import detection
May 23 16:18:47   File "/opt/conda/lib/python3.6/site-packages/torchvision/models/detection/__init__.py", line 1, in <module>
May 23 16:18:47     from .faster_rcnn import *
May 23 16:18:47   File "/opt/conda/lib/python3.6/site-packages/torchvision/models/detection/faster_rcnn.py", line 7, in <module>
May 23 16:18:47     from torchvision.ops import misc as misc_nn_ops
May 23 16:18:47   File "/opt/conda/lib/python3.6/site-packages/torchvision/ops/__init__.py", line 1, in <module>
May 23 16:18:47     from .boxes import nms, box_iou
May 23 16:18:47   File "/opt/conda/lib/python3.6/site-packages/torchvision/ops/boxes.py", line 2, in <module>
May 23 16:18:47     from torchvision import _C
May 23 16:18:47 ImportError: /opt/conda/lib/python3.6/site-packages/torchvision/_C.cpython-36m-x86_64-linux-gnu.so: undefined symbol: _ZN2at19NonVariableTypeMode10is_enabledEv

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@yf225 is landing this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[facebook-github-bot]

@yf225 merged this pull request in 2d96876.