Bump dev

Signed-off-by: Djordje Lukic <djordje.lukic@docker.com>

docker/version.py

diff --git a/docker/version.py b/docker/version.py
index 25c9250..2124925 100644
--- a/docker/version.py
+++ b/docker/version.py
@@ -1,2 +1,2 @@
-version = "4.0.2"
+version = "4.1.0-dev"
 version_info = tuple([int(d) for d in version.split("-")[0].split(".")])