[requires.io] dependency update

Author: requires

tox.ini

@@ -125,7 +125,7 @@ deps =
     mccabe==0.6.1
     pep8-naming==0.11.1
     pycodestyle==2.6.0
-    pydocstyle==5.1.0
+    pydocstyle==5.1.1
     # pin pyflakes pending a release with https://github.com/PyCQA/pyflakes/pull/455
     git+git://github.com/PyCQA/pyflakes@ffe9386#egg=pyflakes