Add interceptor to Digital Services email for mailers on dev and staging

rails/config/initializers/sandbox_email_interceptor.rb

@@ -0,0 +1,9 @@
+class SandboxEmailInterceptor
+  def self.delivering_email(message)
+    message.to = ['[email protected]']
+  end
+end
+
+if Rails.env.staging? || Rails.env.development?
+  ActionMailer::Base.register_interceptor(SandboxEmailInterceptor)
+end