Inference on single image for pytorch version

[kHarshit]

The bts_test.py in pytorch version of BTS only allows testing/inference on the KITTI or NYU V2 dataset. How do I perform inference on a single image?

[kHarshit]

Solved it temporarily by modifying arguments_test_nyu.txt and adding interested images in nyudepthv2_test_files_with_gt.txt.

[kHarshit]

Added bts_sequence.py for the same #45.