Bump skylight from 1.5.1 to 1.6.1

Bumps [skylight](https://github.com/skylightio/skylight-ruby) from 1.5.1 to 1.6.1.
- [Release notes](https://github.com/skylightio/skylight-ruby/releases)
- [Changelog](https://github.com/skylightio/skylight-ruby/blob/master/CHANGELOG.md)
- [Commits](skylightio/skylight-ruby@v1.5.1...v1.6.1)

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

Gemfile.lock

@@ -332,7 +332,7 @@ GEM
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
-    skylight (1.5.1)
+    skylight (1.6.1)
       activesupport (>= 3.0.0)
     spring (2.0.2)
       activesupport (>= 4.2)