Bump sidekiq from 5.1.0 to 5.1.1

Bumps [sidekiq](https://github.com/mperham/sidekiq) from 5.1.0 to 5.1.1.
- [Changelog](https://github.com/mperham/sidekiq/blob/master/Changes.md)
- [Commits](sidekiq/sidekiq@v5.1.0...v5.1.1)

Gemfile.lock

@@ -321,11 +321,11 @@ GEM
       rubyzip (~> 1.2)
     shoulda-matchers (3.1.2)
       activesupport (>= 4.0.0)
-    sidekiq (5.1.0)
+    sidekiq (5.1.1)
       concurrent-ruby (~> 1.0)
       connection_pool (~> 2.2, >= 2.2.0)
       rack-protection (>= 1.5.0)
-      redis (>= 3.3.4, < 5)
+      redis (>= 3.3.5, < 5)
     simplecov (0.15.1)
       docile (~> 1.1.0)
       json (>= 1.8, < 3)