[STYLE] run autopep8 and isort (#421)

Run:
```
isort ./python
autopep8 -i --ignore E501,E701,E731 $(find ./python/ -name '*.py')
```
with an `.isort.cfg` and then clean up a few warts. This PR should be a no-op; the idea is that this is all boring whitespace changes, and any config file changes will be in a different change to make it easier to review.

python/test/unit/runtime/test_comm.py

@@ -1,9 +1,11 @@
-import torch
-import triton
-import pytest
 import subprocess
-import triton.language as tl
+
 import numpy as np
+import pytest
+import torch
+
+import triton
+import triton.language as tl
 
 
 def get_p2p_matrix():