interfaces: create a new folder for interfaces and move repository.py in it I was trying to understand current interfaces and write new ones and I realized we need to improve how current interfaces are organised. This creates a dedicated folder for defining interfaces and move `repository.py` which defines all the current interfaces inside it. Differential Revision: https://phab.mercurial-scm.org/D6741

--- a/tests/pullext.py	Thu Aug 22 16:47:31 2019 -0700
+++ b/tests/pullext.py	Sun Aug 18 00:45:33 2019 +0300
@@ -13,6 +13,8 @@
     error,
     extensions,
     localrepo,
+)
+from mercurial.interfaces import (
     repository,
 )