Refactor budget's phase max description lenght from Budget to Phase model

app/models/budget.rb

@@ -41,10 +41,6 @@ class Budget < ActiveRecord::Base
     send("description_#{phase}").try(:html_safe)
   end
 
-  def self.description_max_length
-    2000
-  end
-
   def self.title_max_length
     80
   end

app/models/budget/phase.rb

@@ -1,5 +1,6 @@
 class Budget
   class Phase < ActiveRecord::Base
+    DESCRIPTION_MAX_LENGTH = 2000
 
     belongs_to :budget
     belongs_to :next_phase, class_name: 'Budget::Phase', foreign_key: :next_phase_id
@@ -7,7 +8,7 @@ class Budget
 
     validates :budget, presence: true
     validates :kind, presence: true, uniqueness: { scope: :budget }, inclusion: { in: Budget::PHASES }
-    validates :description, length: { maximum: Budget.description_max_length }
+    validates :description, length: { maximum: DESCRIPTION_MAX_LENGTH }
     validate :dates_range_valid?
 
     scope :enabled,           -> { where(enabled: true) }

app/views/admin/budgets/_form.html.erb

@@ -4,7 +4,7 @@
 
   <% Budget::PHASES.each do |phase| %>
     <div class="margin-top">
-      <%= f.cktext_area "description_#{phase}", maxlength: Budget.description_max_length, ckeditor: { language: I18n.locale } %>
+      <%= f.cktext_area "description_#{phase}", maxlength: Budget::Phase::DESCRIPTION_MAX_LENGTH, ckeditor: { language: I18n.locale } %>
     </div>
   <% end %>