setup.cfg: update classifiers

- ara isn't openstack specific
- ara is known to work and is tested with 3.8, add it
- definitely not beta software anymore, it's stable and used in production

Change-Id: I89445dc9febdd59da57fc7abb01ce89aa49ab3e7

setup.cfg

@@ -7,7 +7,6 @@ author = OpenStack Community
 author-email = openstack-discuss@lists.openstack.org
 home-page = https://github.com/ansible-community/ara
 classifier =
-    Environment :: OpenStack
     Intended Audience :: Information Technology
     Intended Audience :: System Administrators
     Intended Audience :: Developers
@@ -19,7 +18,8 @@ classifier =
     Programming Language :: Python :: 3.5
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
-    Development Status :: 4 - Beta
+    Programming Language :: Python :: 3.8
+    Development Status :: 5 - Production/Stable
 
 [global]
 setup-hooks =