fix the version of opencv-python (#1829)

Summary:
According to the [upstream issue](opencv/opencv-python#885), opencv-python has a compatibility problem with numpy. Since we fixed the numpy version in the requirements.txt, we also need to fix the opencv-python's verison too. I install the nightly Torch and TorchBench, there is an TorchBench installation error same with the above issue with opencv-python 4.8. But opencv-python 4.7.0.72 works well. I think we'd better fix its version until the latest opencv-python 4.9.0 released.

Pull Request resolved: #1829

Reviewed By: xuzhao9

Differential Revision: D48439448

Pulled By: FindHao

fbshipit-source-id: da34057de3908f30f19d9999aeab800b512a49df

requirements.txt

@@ -17,6 +17,8 @@ pyyaml
 # pytorch build script pins numpy version
 # https://github.com/pytorch/builder/blob/ae5c82e65cb3d8bac6df50e742a195019af91ad3/wheel/build_wheel.sh#L145
 numpy==1.21.2
+# https://github.com/opencv/opencv-python/issues/885
+opencv-python==4.7.0.72
 # Need https://github.com/kornia/kornia/commit/53808e5 to work on PyTorch nightly
 git+https://github.com/kornia/kornia.git@b7050c3
 submitit