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/mercurial/exchange.py	Thu Aug 22 16:47:31 2019 -0700
+++ b/mercurial/exchange.py	Sun Aug 18 00:45:33 2019 +0300
@@ -34,7 +34,6 @@
     phases,
     pushkey,
     pycompat,
-    repository,
     scmutil,
     sslutil,
     streamclone,
@@ -42,6 +41,9 @@
     util,
     wireprototypes,
 )
+from .interfaces import (
+    repository,
+)
 from .utils import (
     stringutil,
 )