Redirect to https also on staging

config.ru

@@ -4,6 +4,7 @@ ENV['RAILS_ENV']  = ENV['RACK_ENV']
 
 $: << 'lib'
 require 'travis/web'
+require 'rack-ssl'
 
 class RedirectSubdomain < Struct.new(:app, :from)
   def call(env)

lib/travis/web/app.rb

@@ -32,7 +32,8 @@ class Travis::Web::App
 
     def build(options = {})
       builder = Rack::Builder.new
-      if options[:environment] == 'production'
+      if options[:environment] == 'production' ||
+          options[:environment] == 'staging'
         builder.use Rack::SSL, hsts: Travis.config.ssl.hsts
       end
       builder.use Rack::Deflater