Generate dashbaord for PaperTrail::Version

```
rails generate administrate:dashboard PaperTrail::Version
```

app/controllers/admin/versions_controller.rb

@@ -0,0 +1,21 @@
+module Admin
+  class PaperTrail::VersionsController < Admin::ApplicationController
+    # To customize the behavior of this controller,
+    # you can overwrite any of the RESTful actions. For example:
+    #
+    # def index
+    #   super
+    #   @resources = PaperTrail::Version.
+    #     page(params[:page]).
+    #     per(10)
+    # end
+
+    # Define a custom finder by overriding the `find_resource` method:
+    # def find_resource(param)
+    #   PaperTrail::Version.find_by!(slug: param)
+    # end
+
+    # See https://administrate-prototype.herokuapp.com/customizing_controller_actions
+    # for more information
+  end
+end

app/dashboards/version_dashboard.rb

@@ -0,0 +1,58 @@
+require "administrate/base_dashboard"
+
+class PaperTrail::VersionDashboard < Administrate::BaseDashboard
+  # ATTRIBUTE_TYPES
+  # a hash that describes the type of each of the model's fields.
+  #
+  # Each different type represents an Administrate::Field object,
+  # which determines how the attribute is displayed
+  # on pages throughout the dashboard.
+  ATTRIBUTE_TYPES = {
+    item: Field::Polymorphic,
+    id: Field::Number,
+    event: Field::String,
+    whodunnit: Field::String,
+    object: Field::Text,
+    created_at: Field::DateTime,
+  }.freeze
+
+  # COLLECTION_ATTRIBUTES
+  # an array of attributes that will be displayed on the model's index page.
+  #
+  # By default, it's limited to four items to reduce clutter on index pages.
+  # Feel free to add, remove, or rearrange items.
+  COLLECTION_ATTRIBUTES = [
+    :item,
+    :id,
+    :event,
+    :whodunnit,
+  ].freeze
+
+  # SHOW_PAGE_ATTRIBUTES
+  # an array of attributes that will be displayed on the model's show page.
+  SHOW_PAGE_ATTRIBUTES = [
+    :item,
+    :id,
+    :event,
+    :whodunnit,
+    :object,
+    :created_at,
+  ].freeze
+
+  # FORM_ATTRIBUTES
+  # an array of attributes that will be displayed
+  # on the model's form (`new` and `edit`) pages.
+  FORM_ATTRIBUTES = [
+    :item,
+    :event,
+    :whodunnit,
+    :object,
+  ].freeze
+
+  # Overwrite this method to customize how versions are displayed
+  # across all pages of the admin dashboard.
+  #
+  # def display_resource(version)
+  #   "PaperTrail::Version ##{version.id}"
+  # end
+end