n_plus_one_control 0.3.0

RSpec and Minitest matchers to prevent N+1 queries problem. Evaluates code under consideration several times with different scale factors to make sure that the number of DB queries behaves as expected (i.e. O(1) instead of O(N)). Example: ```ruby context "N+1", :n_plus_one do populate { |n| create_list(:post, n) } specify do expect { get :index }.to perform_constant_number_of_queries end end ```