Add Elo rating system with match entry and CSV upload

- Implement EloCalculator service for 2v2 Euchre matches
- Create background job processing with GoodJob
- Add single match entry form
- Add CSV upload for batch match entry
- Create player rankings view
- Add database schema for matches and elo snapshots

app/actions/admin/matches/upload.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+require "csv"
+
+module EuchreCamp
+  module Actions
+    module Admin
+      module Matches
+        class Upload < EuchreCamp::Action
+          def handle(request, response)
+            response.render(view)
+          end
+        end
+      end
+    end
+  end
+end