Update overlap_validator.rb to allow to provide a custom validation message and title
Update overlap_validator.rb to allow to provide a custom validation message and title

It is now possible to provide a custom validation message and a custom message title 
eg :  
validates :starts_at, :ends_at, :overlap => {message_content: "Two meetings cannot happen at the same time",message_title: "Start time and end time of the meeting"}
robinbortlik/validates_overlap,robinbortlik/validates_overlap,robinbortlik/validates_overlap