Add population integer attribute to Budget::Heading model table

db/migrate/20170621180611_add_population_to_budget_headings.rb

@@ -0,0 +1,5 @@
+class AddPopulationToBudgetHeadings < ActiveRecord::Migration
+  def change
+    add_column :budget_headings, :population, :integer, default: 0
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170613203256) do
+ActiveRecord::Schema.define(version: 20170621180611) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -110,6 +110,7 @@ ActiveRecord::Schema.define(version: 20170613203256) do
     t.integer "group_id"
     t.string  "name",     limit: 50
     t.integer "price",    limit: 8
+    t.integer "population",            default: 0
   end
 
   add_index "budget_headings", ["group_id"], name: "index_budget_headings_on_group_id", using: :btree