Update Docker from 19.03.0 to 20.10.1 on CI/CD

This affects both on Docker daemon server and client in CI/CD
of the project. It does not change the default version of Docker
of the GitLab product.
Signed-off-by: Takuya Noguchi <takninnovationresearch@gmail.com>

.gitlab-ci.yml

@@ -64,7 +64,7 @@ variables:
   BUILD_ASSETS_IMAGE: "false"
   ES_JAVA_OPTS: "-Xms256m -Xmx256m"
   ELASTIC_URL: "http://elastic:changeme@elasticsearch:9200"
-  DOCKER_VERSION: "19.03.0"
+  DOCKER_VERSION: "20.10.1"
   CACHE_CLASSES: "true"
 
   # Preparing custom clone path to reduce space used by all random forks

changelogs/unreleased/296380-update-docker-from-19-03-to-20-10-on-ci-cd-of-gitlab.yml

+---
+title: Update Docker from 19.03.0 to 20.10.1 on CI/CD
+merge_request: 50732
+author: Takuya Noguchi
+type: other