Merge pull request #509 from kevin-bates/bump-core

Increase minimum jupyter_core dependency

Author: blink1073

setup.cfg

@@ -33,7 +33,7 @@ install_requires =
     argon2-cffi
     ipython_genutils
     traitlets>=4.2.1
-    jupyter_core>=4.4.0
+    jupyter_core>=4.6.0
     jupyter_client>=6.1.1
     jupyter_packaging~=0.9
     nbformat