Add created_by user to Task

db/migrate/20181205000000_add_user_to_task.rb

@@ -0,0 +1,11 @@
+class AddUserToTask < ActiveRecord::Migration
+  def change
+    add_column :tasks, :created_by_user_id, :integer
+
+    reversible do |dir|
+      dir.up do
+        change_column :tasks, :description, :text
+      end
+    end
+  end
+end