Adds the roughest beginnings of a collection model and adds a single field to northeastern_dublin_core_datastream.rb
Refactored datastream models/specs to live app/models and spec/models for the moment; nesting them in datastream directories was causing problems.  Removed double-inclusion of rspec-rails in the Gemfile; it is now only included for the :development and :test groups.
Merge pull request #41 from nu-lts/feature/flatten_model_directories

Feature/flatten model directories