Make tests independent on mailer settings

So tests won't fail when institutions change these default settings.

spec/mailers/dashboard/mailer_spec.rb

@@ -11,6 +11,8 @@ describe Dashboard::Mailer do
 
   before do
     Setting["feature.dashboard.notification_emails"] = true
+    Setting["mailer_from_name"] = "CONSUL"
+    Setting["mailer_from_address"] = "noreply@consul.dev"
   end
 
   describe "#forward" do