Refactor exports controller (#1567)

* Add basic coverage for settings/exports controller

* Remove unused @account variable from settings/exports controller

* Add coverage for download export actions

* Remove deprecated `render :text` in favor of `send_data` for csv downloads

* Add model to handle exports

* Use Export class in settings/exports controller

* Simplify settings/exports controller methods

* Move settings/export to more restful routes

spec/controllers/settings/exports/blocked_accounts_controller_spec.rb

@@ -0,0 +1,17 @@
+require 'rails_helper'
+
+describe Settings::Exports::BlockedAccountsController do
+  before do
+    sign_in Fabricate(:user), scope: :user
+  end
+
+  describe 'GET #index' do
+    it 'returns a csv of the blocking accounts' do
+      get :index, format: :csv
+
+      expect(response).to have_http_status(:success)
+      expect(response.content_type).to eq 'text/csv'
+      expect(response.headers['Content-Disposition']).to eq 'attachment; filename="blocking.csv"'
+    end
+  end
+end