Classes will not be in session in at least three metro Detroit school districts today as teachers join thousands of people protesting against right-to-work legislation in Lansing.  Officials with Taylor Public Schools, Warren Consolidated Schools and Fitzgerald Public Schools in Warren, decided to cancel classes because many teachers and staff will be attending the demonstration.  Opponents of making Michigan the 24th state in the nation to have a right-to-work law say the measure is an attempt to break unions, while supporters say it will attract more business.  Governor Rick Snyder has said he'll sign the legislation when it comes to his desk.