Add __version__ attr to root namespace

for sake of `setup.cfg`

rattail_fabric2/__init__.py

@@ -27,6 +27,8 @@ This package contains various tasks and associated functions for use with
 Fabric deployment and maintenance.
 """
 
+from ._version import __version__
+
 from .core import (
     is_debian,
     get_debian_version,