Add user (ID and type) to proxy exercise

This is required for the existing policies to work

db/migrate/20181119161514_add_user_to_proxy_exercise.rb

@@ -0,0 +1,9 @@
+class AddUserToProxyExercise < ActiveRecord::Migration[5.2]
+  def change
+    add_reference :proxy_exercises, :user,  polymorphic: true, index: true
+    add_column :proxy_exercises, :public, :boolean, null: false, default: false
+
+    internal_user = InternalUser.find_by(id: 46)
+    ProxyExercise.update_all(user_id: internal_user.id, user_type: internal_user.class.name)
+  end
+end

db/schema.rb

@@ -263,6 +263,10 @@ ActiveRecord::Schema.define(version: 2018_11_29_093207) do
     t.string "token"
     t.datetime "created_at"
     t.datetime "updated_at"
+    t.string "user_type"
+    t.bigint "user_id"
+    t.boolean "public"
+    t.index ["user_type", "user_id"], name: "index_proxy_exercises_on_user_type_and_user_id"
   end
 
   create_table "remote_evaluation_mappings", force: :cascade do |t|