import bugfix (#46)

Summary:
```
  File "/workspace/optimizers/distributed_shampoo/distributed_shampoo.py", line 20, in <module>
    from distributed_shampoo.shampoo_types import (
  File "/workspace/optimizers/distributed_shampoo/shampoo_types.py", line 15, in <module>
    from commons import AbstractDataclass
ModuleNotFoundError: No module named 'commons'
```

after fix

```
python -c "from distributed_shampoo.distributed_shampoo import DistributedShampoo;
shampoo_optimizer = DistributedShampoo;
print(shampoo_optimizer)"
<class 'distributed_shampoo.distributed_shampoo.DistributedShampoo'>
```

Pull Request resolved: #46

Reviewed By: anana10c

Differential Revision: D65886425

Pulled By: tsunghsienlee

fbshipit-source-id: e0f4658578dc1c02dfee8f96834e17c2a2ed12e2

pyproject.toml

@@ -52,6 +52,7 @@ Repository = "https://github.com/facebookresearch/optimizers.git"
 [tool.setuptools]
 include-package-data = false
 py-modules = [
+    "commons",
     "matrix_functions",
     "matrix_functions_types",
     "optimizer_modules",