Update development status

setup.py

@@ -60,7 +60,7 @@ setup(
     scripts=["bin/radicale"],
     keywords=["calendar", "addressbook", "CalDAV", "CardDAV"],
     classifiers=[
-        "Development Status :: 4 - Beta",
+        "Development Status :: 5 - Production/Stable",
         "Environment :: Console",
         "Environment :: Web Environment",
         "Intended Audience :: End Users/Desktop",