Move all the gradual typing stuff into one folder

jedi/plugins/__init__.py

@@ -1,5 +1,4 @@
 from jedi.plugins.stdlib import StdlibPlugin
-from jedi.plugins.typeshed import TypeshedPlugin
 from jedi.plugins.flask import FlaskPlugin
 
 
@@ -35,5 +34,4 @@ class _PluginCallbacks(object):
 plugin_manager = _PluginManager([
     StdlibPlugin,
     FlaskPlugin,
-    TypeshedPlugin,
 ])