Add torchao.__version__ (#359)

* Add torchao.__version__

* push

torchao/__init__.py

@@ -1,11 +1,20 @@
 import torch
 import logging
 
+# We use this "hack" to set torchao.__version__ correctly
+# the version of ao is dependent on environment variables for multiple architectures
+# For local development this will default to whatever is version.txt
+# For release builds this will be set the version+architecture_postfix
+from importlib.metadata import version, PackageNotFoundError
+try:
+    __version__ = version("torchao")
+except PackageNotFoundError:
+    __version__ = 'unknown'  # In case this logic breaks don't break the build
+
 _IS_FBCODE = (
     hasattr(torch._utils_internal, "IS_FBSOURCE") and
     torch._utils_internal.IS_FBSOURCE
 )
-
 if not _IS_FBCODE:
     try:
         from . import _C