Allow root URL to redirect to a conference via ENV var.

spec/routing/routing_spec.rb

@@ -0,0 +1,28 @@
+require 'spec_helper'
+
+feature 'Routing', type: :routing do
+  let(:conference) { create(:conference) }
+
+  context 'the root URL' do
+    it 'routes to conferences#index' do
+      expect(get: '/').to route_to(
+        controller: 'conferences',
+        action:     'index'
+      )
+    end
+
+    # FIXME: this doesn't work due to routes being statically loaded
+    # See https://github.com/rspec/rspec-rails/issues/817 for example
+    # context 'with OSEM_ROOT_CONFERENCE set' do
+    #   it 'redirects to the conference' do
+    #     ClimateControl.modify OSEM_ROOT_CONFERENCE: conference.short_title do
+    #       expect(get: '/').to route_to(
+    #         controller: 'conferences',
+    #         action:     'show',
+    #         id:         conference.short_title
+    #       )
+    #     end
+    #   end
+    # end
+  end
+end