minor fix in setup.py (comma before appnope)

Author: jstriebel

setup.py

@@ -80,7 +80,7 @@ def run(self):
         'traitlets>=4.1.0',
         'jupyter_client',
         'tornado>=4.2',
-        'matplotlib-inline>=0.1.0,<0.2.0'
+        'matplotlib-inline>=0.1.0,<0.2.0',
         'appnope;platform_system=="Darwin"',
     ],
     extras_require={