Bump skylight from 4.2.0 to 4.2.1 (publiclab#7243)

Bumps [skylight](https://github.com/skylightio/skylight-ruby) from 4.2.0 to 4.2.1.
- [Release notes](https://github.com/skylightio/skylight-ruby/releases)
- [Changelog](https://github.com/skylightio/skylight-ruby/blob/v4.2.1/CHANGELOG.md)
- [Commits](skylightio/skylight-ruby@v4.2.0...v4.2.1)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Gemfile.lock

@@ -212,7 +212,7 @@ GEM
     http_accept_language (2.1.1)
     http_parser.rb (0.6.0)
     httpclient (2.8.3)
-    i18n (1.8.1)
+    i18n (1.8.2)
       concurrent-ruby (~> 1.0)
     i18n-js (3.5.1)
       i18n (>= 0.6.6)
@@ -275,7 +275,7 @@ GEM
     mimemagic (0.3.3)
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
-    minitest (5.13.0)
+    minitest (5.14.0)
     minitest-reporters (1.4.2)
       ansi
       builder
@@ -487,9 +487,9 @@ GEM
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
-    skylight (4.2.0)
-      skylight-core (= 4.2.0)
-    skylight-core (4.2.0)
+    skylight (4.2.1)
+      skylight-core (= 4.2.1)
+    skylight-core (4.2.1)
       activesupport (>= 4.2.0)
     sprockets (3.7.2)
       concurrent-ruby (~> 1.0)