Add support for stop_grace_period in v2

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

compose/config/config_schema_v2.0.json

@@ -192,6 +192,7 @@
         "security_opt": {"type": "array", "items": {"type": "string"}, "uniqueItems": true},
         "shm_size": {"type": ["number", "string"]},
         "stdin_open": {"type": "boolean"},
+        "stop_grace_period": {"type": "string", "format": "duration"},
         "stop_signal": {"type": "string"},
         "tmpfs": {"$ref": "#/definitions/string_or_list"},
         "tty": {"type": "boolean"},

compose/config/config_schema_v2.1.json

@@ -217,6 +217,7 @@
         "shm_size": {"type": ["number", "string"]},
         "sysctls": {"$ref": "#/definitions/list_or_dict"},
         "stdin_open": {"type": "boolean"},
+        "stop_grace_period": {"type": "string", "format": "duration"},
         "stop_signal": {"type": "string"},
         "tmpfs": {"$ref": "#/definitions/string_or_list"},
         "tty": {"type": "boolean"},

compose/config/config_schema_v3.0.json

@@ -169,8 +169,8 @@
         "shm_size": {"type": ["number", "string"]},
         "sysctls": {"$ref": "#/definitions/list_or_dict"},
         "stdin_open": {"type": "boolean"},
-        "stop_signal": {"type": "string"},
         "stop_grace_period": {"type": "string", "format": "duration"},
+        "stop_signal": {"type": "string"},
         "tmpfs": {"$ref": "#/definitions/string_or_list"},
         "tty": {"type": "boolean"},
         "ulimits": {