feat(registry): track last-seen index in registry.watch
feat(registry): track last-seen index in registry.watch

giantswarm/fleet,improbable-io/fleet,ecnahc515/fleet,hhoover/fleet,esatterwhite/fleet,mwitkow/fleet,bviswana101/fleet,dalbani/fleet,flandr/fleet,coreos/fleet,mwitkow-io/fleet,endocode/fleet,endocode/fleet,wuqixuan/fleet,webwlsong/fleet,jonboulle/fleet,paveltiunov/fleet,mookjp/fleet,WPMedia/fleet,wuqixuan/fleet,dongsupark/fleet,thepwagner/fleet,improbable-io/fleet,bcwaldon/fleet,mwhooker/fleet,thepwagner/fleet,coreos/fleet,bcwaldon/fleet,jonboulle/fleet,mischief/fleet,coreos/fleet,endocode/fleet,octoblu/fleet,bcwaldon/fleet,ecnahc515/fleet,giantswarm/fleet,ecnahc515/fleet,webwlsong/fleet,improbable-io/fleet,mwitkow-io/fleet,giantswarm/fleet,paveltiunov/fleet,mookjp/fleet,jonboulle/fleet,flandr/fleet,dalbani/fleet,dongsupark/fleet,mwitkow/fleet,WPMedia/fleet,mischief/fleet,hhoover/fleet,dalbani/fleet,esatterwhite/fleet,dongsupark/fleet,octoblu/fleet,bviswana101/fleet,mwhooker/fleet