Merge branch 'bw-remove-constant-warnings' into 'master'

Remove 'already initialized constant' warnings

See merge request gitlab-org/gitlab-ce!28518

spec/support/helpers/stub_configuration.rb

@@ -2,7 +2,8 @@ require 'active_support/core_ext/hash/transform_values'
 require 'active_support/hash_with_indifferent_access'
 require 'active_support/dependencies'
 
-require_dependency 'gitlab'
+# check gets rid of already initialized constant warnings when using spring
+require_dependency 'gitlab' unless defined?(Gitlab)
 
 module StubConfiguration
   def stub_application_setting(messages)