Standardize headers and docstrings (#4417)

* Implement new headers

* Reformat 1

* Reformat 2

* Reformat 3 - math

* Reformat 4 - yaml

utils/torch_utils.py

@@ -1,7 +1,11 @@
-# YOLOv5 PyTorch utils
+# YOLOv5 🚀 by Ultralytics, GPL-3.0 license
+"""
+PyTorch utils
+"""
 
 import datetime
 import logging
+import math
 import os
 import platform
 import subprocess
@@ -10,7 +14,6 @@ from contextlib import contextmanager
 from copy import deepcopy
 from pathlib import Path
 
-import math
 import torch
 import torch.backends.cudnn as cudnn
 import torch.distributed as dist