Minimum version 1.24 -> 1.21

Signed-off-by: Joffrey F <[email protected]>

Author: shin-

docker/constants.py

@@ -2,7 +2,7 @@
 from .version import version
 
 DEFAULT_DOCKER_API_VERSION = '1.24'
-MINIMUM_DOCKER_API_VERSION = '1.24'
+MINIMUM_DOCKER_API_VERSION = '1.21'
 DEFAULT_TIMEOUT_SECONDS = 60
 STREAM_HEADER_SIZE_BYTES = 8
 CONTAINER_LIMITS_KEYS = [