Add basic REST API

app/api/repp/api.rb

@@ -0,0 +1,22 @@
+module Repp
+  class API < Grape::API
+    format :json
+    prefix :repp
+    version 'v1', using: :path
+
+    http_basic do |username, password|
+      @current_user ||= EppUser.find_by(username: username, password: password)
+    end
+
+    helpers do
+      attr_reader :current_user
+    end
+
+    resource :domains do
+      desc 'Return list of domains'
+      get '/' do
+        current_user.registrar.domains
+      end
+    end
+  end
+end