Add release tracking for Sentry

config/initializers/2_app.rb

@@ -3,6 +3,6 @@ module Gitlab
     Settings
   end
 
-  VERSION = File.read(Rails.root.join("VERSION")).strip
-  REVISION = Gitlab::Popen.popen(%W(#{config.git.bin_path} log --pretty=format:%h -n 1)).first.chomp
+  VERSION  = File.read(Rails.root.join("VERSION")).strip.freeze
+  REVISION = Gitlab::Popen.popen(%W(#{config.git.bin_path} log --pretty=format:%h -n 1)).first.chomp.freeze
 end

config/initializers/sentry.rb

@@ -14,6 +14,7 @@ if Rails.env.production?
   if sentry_enabled
     Raven.configure do |config|
       config.dsn = current_application_settings.sentry_dsn
+      config.release = Gitlab::REVISION
     end
   end
 end