Add eager_load config to avoid warnings on tests

In order to avoid:
```
config.eager_load is set to nil. Please update your config/environments/*.rb files accordingly:

  * development - set it to false
  * test - set it to false (unless you use a tool that preloads your test environment)
  * production - set it to true
``` 
on tests, we could add those as described.

review @schneems