fix classifiers

setup.py

@@ -22,7 +22,7 @@ setup(
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Console',
-        'Intended Audience :: End Users/Desktop'
+        'Intended Audience :: End Users/Desktop',
         'License :: OSI Approved :: MIT License',
         'Programming Language :: Python :: 3',
         'Topic :: Security :: Cryptography',