Rename README.md to README so it can be shared between setup.py and github.

Author: mikelward

README.md README

@@ -20,7 +20,7 @@
 
 setup(name='ipaddr',
       description="Google's IP address manipulation library",
-      long_description=open('README.md').read(),
+      long_description=open('README').read(),
       maintainer='Google',
       maintainer_email='[email protected]',
       version=ipaddr.__version__,