Backport PR jupyter#2972: update version to dev version for master to not overwrite editable installs (jupyter#2984)

Author: meeseeksdev[bot]

notebook/_version.py

@@ -9,5 +9,5 @@
 
 # Next beta/alpha/rc release: The version number for beta is X.Y.ZbN **without dots**. 
 
-version_info = (5, 2, 0)
+version_info = (5, 3, 0, ".dev0")
 __version__ = '.'.join(map(str, version_info[:3])) + ''.join(version_info[3:])

notebook/static/base/js/namespace.js

@@ -73,7 +73,7 @@ define(function(){
     // tree
     jglobal('SessionList','tree/js/sessionlist');
 
-    Jupyter.version = "5.2.0";
+    Jupyter.version = "5.3.0.dev0";
     Jupyter._target = '_blank';
     return Jupyter;
 });