pin dev requirements

requirements/dev.txt

@@ -1,11 +1,8 @@
 -r compiled.txt
 -r test.txt
 -r docs.txt
+-r flake8.txt
 
 django-debug-toolbar==1.2
 django-fixture-magic==0.0.4
-flake8
-mccabe
-pep8
-pyflakes
-sqlparse
+sqlparse==0.1.14

requirements/flake8.txt

@@ -0,0 +1,4 @@
+flake8==2.3.0
+mccabe==0.3
+pep8==1.5.7
+pyflakes==0.8.1

tox.ini

@@ -37,10 +37,7 @@ commands =
 
 [testenv:flake8]
 deps =
-    flake8
-    mccabe
-    pep8
-    pyflakes
+    -rrequirements/flake8.txt
 commands = make flake8
 
 [testenv:docs]