ADD repositories表中添加is_mirror字段

db/migrate/20200518090640_add_is_mirror_to_repositories.rb

@@ -0,0 +1,5 @@
+class AddIsMirrorToRepositories < ActiveRecord::Migration[5.2]
+  def change
+    add_column :repositories, :is_mirror, :boolean, default: false
+  end
+end