title: NoMethodError in Admin::ApartmentPostsController#create
body: <p>I am using active admin for my admin panel in Ruby on Rails website. I have this code on my ApartmentPost resource.</p>
  
  <pre><code>ActiveAdmin.register ApartmentPost do
  permit_params :title, :max_stay, :min_stay, :bed_configuration, :number_of_guests,
                          :features, :description, :admin_user_id, :apartment_number,:latitude, :longitude, :clean_fee, :country, :location, photos: []
  
   form(html: { multipart: true }) do |f|
  f.inputs do
    f.input :title
    f.input :max_stay
    f.input :min_stay
    f.input :bed_configuration
    f.input :number_of_guests
    f.input :features
    f.input :description
    f.input :country
    f.input :location
    f.input :apartment_number
    f.input :latitude
    f.input :longitude
    f.input :clean_fee
    f.input :admin_user_id, as: :hidden, input_html: {value: current_admin_user.id}
    f.file_field :photos, multiple: true
  end
  f.actions
  end
  </code></pre>
  
  <p>So the error I am getting is while creating a new ApartmentPost. The error is:</p>
  
  <p><a href="https://i.stack.imgur.com/Lpvl2.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Lpvl2.png" alt="enter image description here"></a></p>
  
  <p>I had created a column called rate in AparmentPost but now it is already removed. Still it gives this error.</p>
  
  <p>Here's the table from schema.rb:</p>
  
  <pre><code>create_table "apartment_posts", force: :cascade do |t|
  t.integer  "admin_user_id",                   null: false
  t.integer  "max_stay",                        null: false
  t.string   "bed_configuration",               null: false
  t.integer  "number_of_guests",                null: false
  t.string   "features",                        null: false
  t.string   "description",                     null: false
  t.json     "photos"
  t.datetime "created_at",                      null: false
  t.datetime "updated_at",                      null: false
  t.string   "title",                           null: false
  t.string   "country",                         null: false
  t.string   "apartment_number",                null: false
  t.string   "latitude"
  t.string   "longitude"
  t.integer  "min_stay",                        null: false
  t.string   "location",                        null: false
  t.integer  "clean_fee",         default: 100, null: false
  t.integer  "property_type_id"
  t.index ["admin_user_id"], name: "index_apartment_posts_on_admin_user_id", using: :btree
  t.index ["property_type_id"], name: "index_apartment_posts_on_property_type_id", using: :btree
  end
  </code></pre>
  
  <p>Here's the code in routes.rb</p>
  
  <pre><code>devise_for :admin_users, ActiveAdmin::Devise.config
  ActiveAdmin.routes(self)
  </code></pre>
  
  <p>I am new in Rails and Active Admin. I tried searching the solution everywhere even tried uninstalling active_admin gem and installing again and removing apartment_post resource and generating it again but none og them worked. </p>