Acts as votable. Trying to make it so that users don't have to sign in to upvote/downvote.

guides_controller.rb

  def upvote
    @guide = Guide.find(params[:id])
    @guide.liked_by current_user
    redirect_to :back
  end

  def downvote
    @guide = Guide.find(params[:id])
    @guide.downvote_from current_user
    redirect_to :back
  end

routes.rb

  resources :guides do
    member do
      put "like", to: "guides#upvote"
      put "dislike", to: "guides#downvote"
    end
  end