Description of problem:
----------------------
This error is seen in the production.log file.

Snippet from production.log:
[----] I, [2016-10-12T13:23:02.730359 #11810:1686784]  INFO -- : Started GET "/favicon.ico" for 127.0.0.1 at 2016-10-12 13:23:02 -0400
[----] F, [2016-10-12T13:23:02.732612 #11810:1686784] FATAL -- :
[----] F, [2016-10-12T13:23:02.732703 #11810:1686784] FATAL -- : ActionController::RoutingError (No route matches [GET] "/favicon.ico"):
[----] F, [2016-10-12T13:23:02.732758 #11810:1686784] FATAL -- :
[----] F, [2016-10-12T13:23:02.732801 #11810:1686784] FATAL -- : actionpack (5.0.0.1) lib/action_dispatch/middleware/debug_exceptions.rb:53:in `call'
[----] F, [2016-10-12T13:23:02.732841 #11810:1686784] FATAL -- : actionpack (5.0.0.1) lib/action_dispatch/middleware/show_exceptions.rb:31:in `call'
[----] F, [2016-10-12T13:23:02.732907 #11810:1686784] FATAL -- : railties (5.0.0.1) lib/rails/rack/logger.rb:36:in `call_app'
[----] F, [2016-10-12T13:23:02.732948 #11810:1686784] FATAL -- : railties (5.0.0.1) lib/rails/rack/logger.rb:26:in `call'
[----] F, [2016-10-12T13:23:02.733052 #11810:1686784] FATAL -- : request_store (1.3.1) lib/request_store/middleware.rb:9:in `call'
[----] F, [2016-10-12T13:23:02.733102 #11810:1686784] FATAL -- : actionpack (5.0.0.1) lib/action_dispatch/middleware/request_id.rb:24:in `call'
[----] F, [2016-10-12T13:23:02.733142 #11810:1686784] FATAL -- : rack (2.0.1) lib/rack/method_override.rb:22:in `call'
[----] F, [2016-10-12T13:23:02.733173 #11810:1686784] FATAL -- : rack (2.0.1) lib/rack/runtime.rb:22:in `call'
[----] F, [2016-10-12T13:23:02.733204 #11810:1686784] FATAL -- : activesupport (5.0.0.1) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
[----] F, [2016-10-12T13:23:02.733234 #11810:1686784] FATAL -- : actionpack (5.0.0.1) lib/action_dispatch/middleware/executor.rb:12:in `call'
[----] F, [2016-10-12T13:23:02.733264 #11810:1686784] FATAL -- : rack (2.0.1) lib/rack/sendfile.rb:111:in `call'
[----] F, [2016-10-12T13:23:02.733294 #11810:1686784] FATAL -- : railties (5.0.0.1) lib/rails/engine.rb:522:in `call'
[----] F, [2016-10-12T13:23:02.733323 #11810:1686784] FATAL -- : puma (3.3.0) lib/puma/configuration.rb:224:in `call'
[----] F, [2016-10-12T13:23:02.733353 #11810:1686784] FATAL -- : puma (3.3.0) lib/puma/server.rb:561:in `handle_request'
[----] F, [2016-10-12T13:23:02.733383 #11810:1686784] FATAL -- : puma (3.3.0) lib/puma/server.rb:406:in `process_client'
[----] F, [2016-10-12T13:23:02.733413 #11810:1686784] FATAL -- : puma (3.3.0) lib/puma/server.rb:271:in `block in run'
[----] F, [2016-10-12T13:23:02.733442 #11810:1686784] FATAL -- : puma (3.3.0) lib/puma/thread_pool.rb:111:in `block in spawn_thread'
[----] I, [2016-10-12T13:23:02.809105 #11810:1686784]  INFO -- : Started GET "/favicon.ico" for 127.0.0.1 at 2016-10-12 13:23:02 -0400


Version-Release number of selected component (if applicable):
--------------------------
5.7.0.4


How reproducible:
-----------------
Not sure


Steps to Reproduce:
------------------
1.
2.
3.


Actual results:
---------------
Routing error in the logs


Expected results:
----------------
No routing error


Additional info:
----------------