try using rack cache for in memory caching

Gemfile

@@ -8,6 +8,7 @@ gem 'sinatra-contrib'
 gem 'yard-sinatra',   github: 'rkh/yard-sinatra'
 gem 'rack-contrib',   github: 'rack/rack-contrib'
 gem 'rack-ssl', '~> 1.3'
+gem 'rack-cache'
 
 group :development, :test do
   gem 'rake', '~> 0.9.2'

Gemfile.lock

@@ -291,6 +291,7 @@ DEPENDENCIES
   mocha (~> 0.12)
   newrelic_rpm (~> 3.3.0)
   pg (~> 0.13.2)
+  rack-cache
   rack-contrib!
   rack-ssl (~> 1.3)
   rake (~> 0.9.2)

lib/travis/web/app.rb

@@ -1,5 +1,6 @@
 require 'rack'
 require 'rack/protection/path_traversal'
+require 'rack/cache'
 
 class Travis::Web::App
   ASSET_DIRS = %r(/(styles|scripts)/)
@@ -31,7 +32,10 @@ class Travis::Web::App
       use Rack::Protection::PathTraversal
 
       use Travis::Web::App::Api, config if config.run_api?
+
+      use Rack::Cache, verbose: true, metastore: 'heap:/', entitystore: 'heap:/' if config.production?
       use Rack::Deflater if config.deflate?
+
       use Travis::Web::App::Assets, config
       use Travis::Web::App::Filter, config
       run Travis::Web::App::Files.new