Merge branch 'ashmckenzie/enable-better-errors-repl' into 'master'

Allow BetterErrors REPL to be enabled

See merge request gitlab-org/gitlab-ce!29034

config/environments/development.rb

@@ -47,4 +47,7 @@ Rails.application.configure do
   config.assets.quiet = true
 
   config.allow_concurrency = defined?(::Puma)
+
+  # BetterErrors live shell (REPL) on every stack frame
+  BetterErrors::Middleware.allow_ip!("127.0.0.1/0")
 end