[Fix] Restructure for wgit availability as a package (#1018)

fairscale/experimental/__init__.py

@@ -9,6 +9,6 @@
 
 from typing import List
 
-from . import nn, optim
+from . import nn, optim, wgit
 
 __all__: List[str] = []

fairscale/experimental/wgit/__init__.py

@@ -3,7 +3,10 @@
 # This source code is licensed under the BSD license found in the
 # LICENSE file in the root directory of this source tree.
 
+from typing import List
+
 from .repo import Repo
 from .version import __version_tuple__
 
 __version__ = ".".join([str(x) for x in __version_tuple__])
+__all__: List[str] = []