Drop Rails3 support

config/environments/development.rb

@@ -7,8 +7,7 @@ Discourse::Application.configure do
   config.cache_classes = false
 
   # Log error messages when you accidentally call methods on nil.
-  config.whiny_nils = true unless rails4?
-  config.eager_load = false if rails4?
+  config.eager_load = false
 
   # Show full error reports and disable caching
   config.consider_all_requests_local       = true
@@ -17,9 +16,6 @@ Discourse::Application.configure do
   # Print deprecation notices to the Rails logger
   config.active_support.deprecation = :log
 
-  # Only use best-standards-support built into browsers
-  config.action_dispatch.best_standards_support = :builtin unless rails4?
-
   # Do not compress assets
   config.assets.compress = false
 

config/environments/production.rb

@@ -12,12 +12,8 @@ Discourse::Application.configure do
   # Disable Rails's static asset server (Apache or nginx will already do this)
   config.serve_static_assets = GlobalSetting.serve_static_assets
 
-  if rails4?
-    config.assets.js_compressor  = :uglifier
-    config.assets.css_compressor = :sass
-  else
-    config.assets.compress = true
-  end
+  config.assets.js_compressor  = :uglifier
+  config.assets.css_compressor = :sass
 
   # stuff should be pre-compiled
   config.assets.compile = false

config/environments/profile.rb

@@ -1,7 +1,7 @@
 Discourse::Application.configure do
   # Settings specified here will take precedence over those in config/application.rb
 
-  config.eager_load = true if rails4?
+  config.eager_load = true
 
   # Code is not reloaded between requests
   config.cache_classes = true

config/environments/test.rb

@@ -41,7 +41,6 @@ Discourse::Application.configure do
   config.assets.digest = false
 
   # silence deprecation warnings in test
-  config.whiny_nils = true unless rails4?
-  config.eager_load = false if rails4?
+  config.eager_load = false
   ActiveSupport::Deprecation.silenced = true
 end