Nuke all votes with score less than 1.

db/migrate/20140427041839_remove_non_votes.rb

@@ -0,0 +1,12 @@
+class RemoveNonVotes < ActiveRecord::Migration
+  class PostVote < ActiveRecord::Base
+  end
+
+  def up
+    PostVote.where('score < 1').delete_all
+  end
+
+  def down
+    ActiveRecord::IrreversibleMigration
+  end
+end