Bump Sidekiq version to 5.0.5

Minor changes: https://github.com/mperham/sidekiq/blob/master/Changes.md

Gemfile.lock

@@ -708,7 +708,7 @@ GEM
       json
     recursive-open-struct (1.0.0)
     redcarpet (3.4.0)
-    redis (3.3.3)
+    redis (3.3.5)
     redis-actionpack (5.0.2)
       actionpack (>= 4.0, < 6)
       redis-rack (>= 1, < 3)
@@ -839,11 +839,11 @@ GEM
       rack
     shoulda-matchers (3.1.2)
       activesupport (>= 4.0.0)
-    sidekiq (5.0.4)
+    sidekiq (5.0.5)
       concurrent-ruby (~> 1.0)
       connection_pool (~> 2.2, >= 2.2.0)
       rack-protection (>= 1.5.0)
-      redis (~> 3.3, >= 3.3.3)
+      redis (>= 3.3.4, < 5)
     sidekiq-cron (0.6.0)
       rufus-scheduler (>= 3.3.0)
       sidekiq (>= 4.2.1)