Merge "Add "fast8" tox env"

tools/fast8.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+cd $(dirname "$0")/..
+CHANGED=$(git diff --name-only HEAD~2 | tr '\n' ' ')
+diff -u --from-file /dev/null $CHANGED | flake8 --diff

tox.ini

@@ -120,6 +120,10 @@ commands =
   {toxinidir}/tools/config/check_uptodate.sh
   {toxinidir}/tools/check_exec.py {toxinidir}/cinder
 
+[testenv:fast8]
+commands =
+  {toxinidir}/tools/fast8.sh
+
 [testenv:pylint]
 deps = -r{toxinidir}/requirements.txt
        pylint==0.26.0