Bump docker-api from 2.2.0 to 2.3.0

Bumps [docker-api](https://github.com/swipely/docker-api) from 2.2.0 to 2.3.0.
- [Release notes](https://github.com/swipely/docker-api/releases)
- [Commits](https://github.com/swipely/docker-api/commits)

---
updated-dependencies:
- dependency-name: docker-api
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Gemfile.lock

@@ -3,10 +3,10 @@ GEM
   specs:
     ansi (1.5.0)
     diff-lcs (1.5.0)
-    docker-api (2.2.0)
-      excon (>= 0.47.0)
+    docker-api (2.3.0)
+      excon (>= 0.64.0)
       multi_json
-    excon (0.84.0)
+    excon (0.111.0)
     hashie (5.0.0)
     itamae (1.14.1)
       ansi