Merge branch 'gitlab-org/gitlab-ci#9' into '4-3-stable'

Support unix sockets for redis connection in sidekiq in branch 4-3-stable

Backward incompatibility regarding config/resque.yml - the schema is required now.
Because of this patch makes it behaving the same way it works in gitlab-ce, I think it is fair enough to handle it here similarly.

See merge request !4

config/initializers/3_sidekiq.rb

@@ -4,19 +4,19 @@ config_file = Rails.root.join('config', 'resque.yml')
 resque_url = if File.exists?(config_file)
                YAML.load_file(config_file)[Rails.env]
              else
-               "localhost:6379"
+               "redis://localhost:6379"
              end
 Sidekiq.configure_server do |config|
   config.redis = {
-    url: "redis://#{resque_url}",
+    url: resque_url,
     namespace: 'resque:gitlab_ci'
   }
 end
 Sidekiq.configure_client do |config|
   config.redis = {
-    url: "redis://#{resque_url}",
+    url: resque_url,
     namespace: 'resque:gitlab_ci'
   }
-end
+end
\ No newline at end of file

config/resque.yml.example

-development: localhost:6379
-test: localhost:6379
-production: redis.example.com:6379
+development: redis://localhost:6379
+test: redis://localhost:6379
+production: redis://redis.example.com:6379
\ No newline at end of file