fix(agent): be more intelligent about starting services
fix(agent): be more intelligent about starting services

* Only write out a unit file if it does not exist
* Only attempt to start the unit if the state is not active

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