Don't pin tornado requirement

mvantellingen · mvantellingen · commit b1617b9bbd7e · 2017-08-26T16:22:07.000+02:00
diff --git a/setup.py b/setup.py
@@ -20,7 +20,7 @@
 ]
 
 tornado_require = [
-    'tornado==4.0.2'
+    'tornado>=4.0.2'
 ]
 
 async_require = []  # see below
