adds spending_proposals counter to Tag

db/migrate/20160104203329_add_spending_proposals_counter_to_tags.rb

@@ -0,0 +1,6 @@
+class AddSpendingProposalsCounterToTags < ActiveRecord::Migration
+  def change
+    add_column :tags, :spending_proposals_count, :integer, default: 0
+    add_index :tags, :spending_proposals_count
+  end
+end