Merge branch 'bump-sidekiq-4.1.2' into 'master'

Upgrade Sidekiq to 4.1.2

Fixes a memory leak: https://github.com/mperham/sidekiq/commit/a2bdb875fe495bc28b1bee80120e4a5641ca0731

See merge request !4056

CHANGELOG

@@ -4,6 +4,7 @@ v 8.8.0 (unreleased)
   - Project#open_branches has been cleaned up and no longer loads entire records into memory.
   - Log to application.log when an admin starts and stops impersonating a user
   - Make build status canceled if any of the jobs was canceled and none failed
+  - Upgrade Sidekiq to 4.1.2
   - Sanitize repo paths in new project error message
   - Bump mail_room to 0.7.0 to fix stuck IDLE connections
   - Remove future dates from contribution calendar graph.

Gemfile.lock

@@ -134,7 +134,7 @@ GEM
       execjs
     coffee-script-source (1.10.0)
     colorize (0.7.7)
-    concurrent-ruby (1.0.1)
+    concurrent-ruby (1.0.2)
     connection_pool (2.2.0)
     coveralls (0.8.13)
       json (~> 1.8)
@@ -740,7 +740,7 @@ GEM
       rack
     shoulda-matchers (2.8.0)
       activesupport (>= 3.0.0)
-    sidekiq (4.1.1)
+    sidekiq (4.1.2)
       concurrent-ruby (~> 1.0)
       connection_pool (~> 2.2, >= 2.2.0)
       redis (~> 3.2, >= 3.2.1)