install older version of tornado for 2.7

bmcculley · bmcculley · commit 6e903dc2709d · 2020-05-26T16:42:37.000-04:00
diff --git a/setup.py b/setup.py
@@ -32,7 +32,8 @@ def version():
         ]
     },
     install_requires=[
-        'tornado',
+        'tornado;python_version>"2.7"',
+        'tornado==5.1.1;python_version=="2.7"',
         'six',
     ],
     license='BSD',
