remove yapf-diff-recursive in favor of yapf 0.17.0

yapf 0.17.0 gained a sensible exit code for yapf --diff:
- google/yapf#325
- google/yapf@71d9b2e

Author: Sarcasm

requirements-dev.txt

@@ -7,4 +7,4 @@ flake8==3.2.0
 pep8-naming==0.4.1
 readme-renderer==17.1
 tox==2.5.0
-yapf==0.16.0
+yapf==0.17.0

tests/integration/yapf-recursive-diff

@@ -15,7 +15,7 @@ commands = python setup.py check -m -r -s
 
 [testenv:lint]
 commands =
-    {toxinidir}/tests/integration/yapf-recursive-diff \
+    yapf --diff --recursive \
         --exclude 'tests/integration/*' \
         --exclude 'tests/regression/headerdb/*' \
         compdb tests setup.py