[requires.io] dependency update

setup.py

@@ -88,7 +88,7 @@
         'dev': [
             "flake8>=3.5, <3.6",
             "Flask>=0.10.1, <0.13",
-            "mypy>=0.550,<0.551",
+            "mypy>=0.560,<0.561",
             "pytest-cov>=2.2.1, <3",
             "pytest-faulthandler>=1.3.0, <2",
             "pytest-timeout>=1.0.0, <2",