Static asset server setting has nothing to do
Static asset server setting has nothing to do

In my Rails 5 app, the following setting will make all UI tests (RSpec System spec) fail.
```ruby
    config.public_file_server.enabled = false
```

I believe that static asset server setting has nothing to do with Spring and SimpleCov.
`config.eager_load = false` is just enough.

For the same reason, for Rails 4 we may not need to set
`config.serve_static_files = false`
but I haven't checked it.
colszowka/simplecov,colszowka/simplecov