Remove custom colour field and use gem

Gemfile

@@ -54,6 +54,7 @@ end
 
 gem 'administrate'
 gem 'administrate-field-image'
+gem 'administrate-field-color'
 gem 'dragonfly'
 gem 'dragonfly-s3_data_store'
 gem 'kaminari'

Gemfile.lock

@@ -48,6 +48,9 @@ GEM
       rails (~> 4.2)
       sass-rails (~> 5.0)
       selectize-rails (~> 0.6)
+    administrate-field-color (0.0.1)
+      administrate (>= 0.2.0.rc1, < 0.3.0)
+      rails (~> 4.2)
     administrate-field-image (0.0.2)
       administrate (>= 0.2.0.rc1, < 0.3.0)
       rails (~> 4.2)
@@ -319,6 +322,7 @@ PLATFORMS
 
 DEPENDENCIES
   administrate
+  administrate-field-color
   administrate-field-image
   aws-sdk
   better_errors

app/dashboards/category_dashboard.rb

@@ -15,7 +15,7 @@ class CategoryDashboard < Administrate::BaseDashboard
     created_at: Field::DateTime,
     updated_at: Field::DateTime,
     photo_id: Field::Number,
-    base_colour: ColourField,
+    base_colour: Field::Color,
     sort: Field::Number,
     slug: Field::String,
   }

app/fields/colour_field.rb

@@ -1,7 +0,0 @@
-require "administrate/field/base"
-
-class ColourField < Administrate::Field::Base
-  def to_s
-    data
-  end
-end

app/views/fields/colour_field/_form.html.erb

@@ -1,6 +0,0 @@
-<div class="field-unit__label">
-  <%= f.label field.attribute %>
-</div>
-<div class="field-unit__field">
-  <%= f.color_field field.attribute, style: 'height: 2.35em; width: 5em;' %>
-</div>

app/views/fields/colour_field/_index.html.erb

@@ -1,2 +0,0 @@
-<%= content_tag :div, nil,
-  style: "height: 1.5em; width: 1.5em; background-color: #{field.data}" %>

app/views/fields/colour_field/_show.html.erb

@@ -1,2 +0,0 @@
-<%= content_tag :span, field.data,
-  style: "color: white; padding: 0.2em 0.5em; background-color: #{field.data}" %>