module Roda::RodaPlugins::DefaultHeaders

def self.configure(app, headers={})

Merge the given headers into the existing default headers, if any. 
def self.configure(app, headers={})
  app.opts[:default_headers] = (app.opts[:default_headers] || {}).merge(headers)
  app.opts[:default_headers].extend(RodaDeprecateMutation)
end