Unbreak image assets due to heroic-deflater bug

romanbsd/heroku-deflater#54

Gemfile

@@ -43,7 +43,3 @@ group :test do
   gem "factory_girl_rails"
   gem "webmock"
 end
-
-group :production do
-  gem "heroku-deflater"
-end

Gemfile.lock

@@ -135,8 +135,6 @@ GEM
       rspec (>= 2.99.0, < 4.0)
     hashdiff (1.0.1)
     hashie (4.1.0)
-    heroku-deflater (0.6.3)
-      rack (>= 1.4.5)
     i18n (1.8.10)
       concurrent-ruby (~> 1.0)
     intercom-rails (0.4.2)
@@ -320,7 +318,6 @@ DEPENDENCIES
   guard
   guard-pow
   guard-rspec
-  heroku-deflater
   intercom-rails
   jbuilder
   listen

config/application.rb

@@ -32,8 +32,10 @@ class Application < Rails::Application
     # config.time_zone = "Central Time (US & Canada)"
     # config.eager_load_paths << Rails.root.join("extras")
 
-    # Use Rack::Deflator for gzipped assets in dev env (in production we use heroku-deflater)
-    config.middleware.use Rack::Deflater if Rails.env.development?
+    # https://github.com/romanbsd/heroku-deflater/issues/54#issuecomment-803400481
+    config.middleware.use Rack::Deflater,
+      include: Rack::Mime::MIME_TYPES.values.grep(/text|json|javascript/).uniq,
+      if: lambda { |env, status, headers, body| body.body.length > 512 }
 
     config.hosts.clear