build(deps): bump excon from 0.81.0 to 1.5.0 in /tests/serverspec

Bumps [excon](https://github.com/excon/excon) from 0.81.0 to 1.5.0.
- [Changelog](https://github.com/excon/excon/blob/master/changelog.txt)
- [Commits](excon/excon@v0.81.0...v1.5.0)

---
updated-dependencies:
- dependency-name: excon
  dependency-version: 1.5.0
  dependency-type: indirect
...

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

Author: dependabot[bot]

tests/serverspec/Gemfile.lock

@@ -5,8 +5,10 @@ GEM
     docker-api (2.1.0)
       excon (>= 0.47.0)
       multi_json
-    excon (0.81.0)
+    excon (1.5.0)
+      logger
     json (2.5.1)
+    logger (1.7.0)
     multi_json (1.15.0)
     net-scp (3.0.0)
       net-ssh (>= 2.6.5, < 7.0.0)