Use underscores for long description

Author: RealOrangeOne

setup.cfg

@@ -2,8 +2,8 @@
 name = django-basic-auth-ip-whitelist
 version = attr: baipw.__version__
 description = Hide your Django site behind basic authentication mechanism with IP whitelisting support.
-long-description = file: README.rst
-long-description-content-type = text/x-rst
+long_description = file: README.rst
+long_description_content_type = text/x-rst
 author = Torchbox
 author_email = hello@torchbox.com
 url = https://github.com/torchbox/django-basic-auth-ip-whitelist