Missing resnet protobuf inference graph in workflows

[McLavish]

Commit 7c7f67b is missing the inference graph for resnet50.

The following needs to be added:

wget http://download.tensorflow.org/models/object_detection/faster_rcnn_resnet50_coco_2018_01_28.tar.gz

tar -xzf faster_rcnn_resnet50_coco_2018_01_28.tar.gz

under:

benchmarks-data/600.workflows/650.vid