[#65] services: Fix docker-compose warnings

There were multiple warning like this one.
```
WARN[0000] /secret/services/rest_gate/docker-compose.yml: `version` is obsolete
```

According to docker-compose spec, the parameter is indeed purely informative:
https://github.com/compose-spec/compose-spec/blob/master/spec.md#version-and-name-top-level-elements

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

services/s3_gate/docker-compose.yml

@@ -1,6 +1,5 @@
 ---
 
-version: "2.4"
 services:
   s3_gate:
     image: ${S3_GW_IMAGE}:${S3_GW_VERSION}