Get secret_token from ENV['SECRET_TOKEN'] (e.g. for Heroku)

Author: Michael Berg

config/initializers/secret_token.rb

@@ -13,6 +13,9 @@
 if Rails.env.test? || Rails.env.development?
   Discourse::Application.config.secret_token = "47f5390004bf6d25bb97083fb98e7cc133ab450ba814dd19638a78282b4ca291"
 else
-  raise "You must set a secret token in config/initializers/secret_token.rb"
+  if Rails.env.production? && ENV['SECRET_TOKEN'].blank?
+    raise 'SECRET_TOKEN environment variable must be set!'
+  end
+  Discourse::Application.config.secret_token = ENV['SECRET_TOKEN']
 end