flak8 lower bounds

Author: Gerry Manoim

setup.py

@@ -24,7 +24,7 @@
         "nose>=1.3.7",
         "parameterized>=0.5.0",
         "tox>=2.3.1",
-        "flake8==3.7.9",
+        "flake8>=3.7.9",
     ],
 }