Update dev status to stable

Author: lpsinger

setup.cfg

@@ -21,7 +21,7 @@ author = Leo Singer
 author_email = leo.singer@ligo.org
 url = https://github.com/lpsinger/pygcn
 classifiers =
-    Development Status :: 4 - Beta
+    Development Status :: 5 - Production/Stable
     Environment :: Console
     Intended Audience :: Science/Research
     License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)