Change Order column from Integer to String

Some Japanese codes for regions start with 0.
We should compare as String rather than Integer.
cf. #219

Author: yasulab

db/migrate/20171211111544_change_order_to_integer.rb

@@ -0,0 +1,6 @@
+class ChangeOrderToInteger < ActiveRecord::Migration[5.1]
+  def change
+    change_column :dojos, :order, :string,  default: '000000'
+  end
+end
+

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20171103042807) do
+ActiveRecord::Schema.define(version: 20171211111544) do
 
   create_table "dojo_event_services", force: :cascade do |t|
     t.integer "dojo_id", null: false
@@ -25,7 +25,7 @@
   create_table "dojos", force: :cascade do |t|
     t.string "name"
     t.string "email"
-    t.integer "order", default: 1
+    t.string "order", default: "000000"
     t.string "description"
     t.string "logo", default: "/logo.png"
     t.string "url", default: "#"