add antivoters (no behavior yet)

db/migrate/20160919234407_create_anti_voters.rb

@@ -0,0 +1,8 @@
+class CreateAntiVoters < ActiveRecord::Migration
+  def change
+    create_table :anti_voters do |t|
+      t.integer :user_id
+      t.timestamps null: false
+    end
+  end
+end