Validaiton Report

Validation Report
  - Update IndexService to get missing field data from Solr
  - Model, controller, routes, and basic views for ValidationReport
  - Rake task to index sample invalid aggregation into Solr
I wonder if this makes more sense to incorporate this using some of the paradigms that Blacklight exposes. For example, see [here](https://github.com/projectblacklight/blacklight/wiki/Extending-or-Modifying-Blacklight-Search-Behavior#application-logic). This would potentially allow us to build out the views as Blacklight views.