Bump version to 0.5.0+dev

src/docs_versions_menu/__init__.py

@@ -4,7 +4,7 @@
 extension and a command line program.
 """
 
-__version__ = '0.5.0'
+__version__ = '0.5.0+dev'
 
 # All members whose name does not start with an underscore must be listed
 # either in __all__ or in __private__