Bump simplecov from 0.18.5 to 0.21.2 (#39)

Bumps [simplecov](https://github.com/simplecov-ruby/simplecov) from 0.18.5 to 0.21.2.
- [Release notes](https://github.com/simplecov-ruby/simplecov/releases)
- [Changelog](https://github.com/simplecov-ruby/simplecov/blob/main/CHANGELOG.md)
- [Commits](simplecov-ruby/simplecov@v0.18.5...v0.21.2)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile.lock

@@ -92,7 +92,7 @@ GEM
       responders
       warden (~> 1.2.3)
     diff-lcs (1.4.4)
-    docile (1.3.2)
+    docile (1.3.5)
     dotenv (2.7.6)
     dotenv-rails (2.7.6)
       dotenv (= 2.7.6)
@@ -228,10 +228,12 @@ GEM
     shoulda-context (2.0.0)
     shoulda-matchers (4.5.1)
       activesupport (>= 4.2.0)
-    simplecov (0.18.5)
+    simplecov (0.21.2)
       docile (~> 1.1)
       simplecov-html (~> 0.11)
-    simplecov-html (0.12.2)
+      simplecov_json_formatter (~> 0.1)
+    simplecov-html (0.12.3)
+    simplecov_json_formatter (0.1.2)
     slim (4.1.0)
       temple (>= 0.7.6, < 0.9)
       tilt (>= 2.0.6, < 2.1)