Allow mkdocs 1.3

Author: Guts

setup.py

@@ -52,7 +52,7 @@
     },
     install_requires=[
         "GitPython>=3.1,<3.2",
-        "mkdocs>=1.1,<1.3",
+        "mkdocs>=1.1,<1.4",
     ],
     # metadata
     keywords="mkdocs rss git plugin",