Start sending updated_at timestamp as edited_at for profiles

This can be used in later diaspora versions to order the profile updates
so we don't overwrite a newer profile with older data.

lib/diaspora/federation/entities.rb

@@ -169,6 +169,7 @@ module Diaspora
       def self.profile(profile)
         DiasporaFederation::Entities::Profile.new(
           author:           profile.diaspora_handle,
+          edited_at:        profile.updated_at,
           first_name:       profile.first_name,
           last_name:        profile.last_name,
           image_url:        profile.image_url,

spec/lib/diaspora/federation/entities_spec.rb

@@ -201,6 +201,7 @@ describe Diaspora::Federation::Entities do
 
       expect(federation_entity).to be_instance_of(DiasporaFederation::Entities::Profile)
       expect(federation_entity.author).to eq(diaspora_entity.diaspora_handle)
+      expect(federation_entity.edited_at).to eq(diaspora_entity.updated_at)
       expect(federation_entity.first_name).to eq(diaspora_entity.first_name)
       expect(federation_entity.last_name).to eq(diaspora_entity.last_name)
       expect(federation_entity.image_url).to eq(diaspora_entity.image_url)