Bump shoulda-matchers from 4.4.1 to 4.5.1

Bumps [shoulda-matchers](https://github.com/thoughtbot/shoulda-matchers) from 4.4.1 to 4.5.1.
- [Release notes](https://github.com/thoughtbot/shoulda-matchers/releases)
- [Changelog](https://github.com/thoughtbot/shoulda-matchers/blob/master/CHANGELOG.md)
- [Commits](thoughtbot/shoulda-matchers@v4.4.1...v4.5.1)

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

Gemfile.lock

@@ -209,7 +209,7 @@ GEM
     ruby-progressbar (1.11.0)
     ruby2_keywords (0.0.2)
     shellany (0.0.1)
-    shoulda-matchers (4.4.1)
+    shoulda-matchers (4.5.1)
       activesupport (>= 4.2.0)
     sidekiq (6.1.3)
       connection_pool (>= 2.2.2)