Move torchvision install out of onnx test script

Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/20890

Differential Revision: D15486657

Pulled By: bddppq

fbshipit-source-id: 3acd7386d1f070cad9bd43d6e74244b706c0dc16

.jenkins/caffe2/test.sh

@@ -120,5 +120,6 @@ pip install --user pytest-sugar
 # torchvision tests #
 #####################
 if [[ "$BUILD_ENVIRONMENT" == *onnx* ]]; then
+  pip install -q --user git+https://github.com/pytorch/vision.git
   "$ROOT_DIR/scripts/onnx/test.sh"
 fi

scripts/onnx/test.sh

@@ -24,20 +24,6 @@ done
 set -- "${UNKNOWN[@]}" # leave UNKNOWN
 
 pip install pytest scipy hypothesis
-
-install_torchvision() {
-  echo "Installing torchvision at branch master"
-  rm -rf vision
-  # TODO: This git clone is bad, it means pushes to torchvision can break
-  # PyTorch CI
-  git clone https://github.com/pytorch/vision --quiet
-  pushd vision
-  pip install -q --user .
-  popd
-  rm -rf vision
-}
-install_torchvision
-
 if [[ $PARALLEL == 1 ]]; then
     pip install pytest-xdist
 fi