pkg: fix typo in clock docstring
pkg: fix typo in clock docstring

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