Fix typo ...

wdv4758h · wdv4758h · commit 3f7b69cecf27 · 2016-06-13T16:06:15.000+08:00
diff --git a/.travis.yml b/.travis.yml
@@ -30,7 +30,7 @@ install:
 
 script:
     - python setup.py test
-    - pycostyle everywhere
+    - pydocstyle everywhere
     - mypy everywhere
 
 after_success:
