Add new 'hide_money' column to the budgets' table

We will use this field to show/hide all price references in the Budgets
with the final voting style: Approval.

db/migrate/20210311110036_add_hide_money_to_budgets.rb

@@ -0,0 +1,5 @@
+class AddHideMoneyToBudgets < ActiveRecord::Migration[5.1]
+  def change
+    add_column :budgets, :hide_money, :boolean, default: false
+  end
+end

db/schema.rb

@@ -394,6 +394,7 @@ ActiveRecord::Schema.define(version: 2021_11_03_112944) do
     t.text "description_informing"
     t.string "voting_style", default: "knapsack"
     t.boolean "published"
+    t.boolean "hide_money", default: false
   end
 
   create_table "campaigns", id: :serial, force: :cascade do |t|