core: clean up machine directory when id = nil
core: clean up machine directory when id = nil

bshurts/vagrant,petems/vagrant,denisbr/vagrant,jberends/vagrant,tbriggs-curse/vagrant,Sgoettschkes/vagrant,crashlytics/vagrant,mpoeter/vagrant,Avira/vagrant,marxarelli/vagrant,sax/vagrant,Avira/vagrant,muhanadra/vagrant,vamegh/vagrant,chrisvire/vagrant,sni/vagrant,PatrickLang/vagrant,myrjola/vagrant,evverx/vagrant,jhoblitt/vagrant,philoserf/vagrant,chrisroberts/vagrant,rivy/vagrant,clinstid/vagrant,p0deje/vagrant,benh57/vagrant,philoserf/vagrant,channui/vagrant,legal90/vagrant,philwrenn/vagrant,Ninir/vagrant,shtouff/vagrant,justincampbell/vagrant,petems/vagrant,benizi/vagrant,bheuvel/vagrant,invernizzi-at-google/vagrant,tbarrongh/vagrant,zsjohny/vagrant,ferventcoder/vagrant,chrisvire/vagrant,lonniev/vagrant,petems/vagrant,jkburges/vagrant,benizi/vagrant,miguel250/vagrant,jfchevrette/vagrant,PatOShea/vagrant,chrisroberts/vagrant,crashlytics/vagrant,taliesins/vagrant,pwnall/vagrant,philwrenn/vagrant,tbarrongh/vagrant,senglin/vagrant,taliesins/vagrant,jberends/vagrant,fnewberg/vagrant,apertoso/vagrant,Endika/vagrant,vamegh/vagrant,mwrock/vagrant,jhoblitt/vagrant,signed8bit/vagrant,juiceinc/vagrant,justincampbell/vagrant,carlosefr/vagrant,bdwyertech/vagrant,gpkfr/vagrant,modulexcite/vagrant,petems/vagrant,mpoeter/vagrant,jmanero/vagrant,tbriggs-curse/vagrant,ianmiell/vagrant,jtopper/vagrant,denisbr/vagrant,gitebra/vagrant,mkuzmin/vagrant,sideci-sample/sideci-sample-vagrant,mwarren/vagrant,kamigerami/vagrant,blueyed/vagrant,invernizzi-at-google/vagrant,kamazee/vagrant,bheuvel/vagrant,Endika/vagrant,vamegh/vagrant,dhoer/vagrant,bshurts/vagrant,lonniev/vagrant,shtouff/vagrant,doy/vagrant,stephancom/vagrant,pwnall/vagrant,senglin/vagrant,dustymabe/vagrant,BlakeMesdag/vagrant,shtouff/vagrant,janek-warchol/vagrant,bdwyertech/vagrant,stephancom/vagrant,philwrenn/vagrant,BlakeMesdag/vagrant,rivy/vagrant,iNecas/vagrant,otagi/vagrant,johntron/vagrant,PatOShea/vagrant,blueyed/vagrant,bryson/vagrant,benh57/vagrant,wkolean/vagrant,aneeshusa/vagrant,kalabiyau/vagrant,crashlytics/vagrant,darkn3rd/vagrant,aaam/vagrant,jberends/vagrant,ArloL/vagrant,Avira/vagrant,aaam/vagrant,muhanadra/vagrant,tomfanning/vagrant,krig/vagrant,mkuzmin/vagrant,pwnall/vagrant,loren-osborn/vagrant,jtopper/vagrant,teotihuacanada/vagrant,dharmab/vagrant,gitebra/vagrant,blueyed/vagrant,sferik/vagrant,mwrock/vagrant,miguel250/vagrant,stephancom/vagrant,juiceinc/vagrant,dhoer/vagrant,crashlytics/vagrant,tomfanning/vagrant,jean/vagrant,zsjohny/vagrant,Chhunlong/vagrant,bryson/vagrant,mitchellh/vagrant,MiLk/vagrant,sax/vagrant,patrys/vagrant,ArloL/vagrant,taliesins/vagrant,Sgoettschkes/vagrant,jfchevrette/vagrant,genome21/vagrant,genome21/vagrant,tjanez/vagrant,carlosefr/vagrant,Chhed13/vagrant,philoserf/vagrant,gajdaw/vagrant,Chhunlong/vagrant,PatrickLang/vagrant,otagi/vagrant,wkolean/vagrant,doy/vagrant,gajdaw/vagrant,gpkfr/vagrant,benizi/vagrant,dustymabe/vagrant,tomfanning/vagrant,gbarberi/vagrant,johntron/vagrant,krig/vagrant,taliesins/vagrant,mwarren/vagrant,cgvarela/vagrant,kamigerami/vagrant,mwarren/vagrant,theist/vagrant,senglin/vagrant,stephancom/vagrant,ferventcoder/vagrant,sferik/vagrant,modulexcite/vagrant,PatOShea/vagrant,philoserf/vagrant,dharmab/vagrant,PatrickLang/vagrant,muhanadra/vagrant,jmanero/vagrant,dhoer/vagrant,TheBigBear/vagrant,wangfakang/vagrant,kamazee/vagrant,blueyed/vagrant,zsjohny/vagrant,shtouff/vagrant,genome21/vagrant,channui/vagrant,loren-osborn/vagrant,benh57/vagrant,lonniev/vagrant,darkn3rd/vagrant,dustymabe/vagrant,tschortsch/vagrant,jkburges/vagrant,teotihuacanada/vagrant,Ninir/vagrant,gpkfr/vagrant,mitchellh/vagrant,theist/vagrant,p0deje/vagrant,MiLk/vagrant,teotihuacanada/vagrant,jfchevrette/vagrant,justincampbell/vagrant,justincampbell/vagrant,nickryand/vagrant,myrjola/vagrant,nickryand/vagrant,chrisroberts/vagrant,patrys/vagrant,chrisvire/vagrant,genome21/vagrant,myrjola/vagrant,bshurts/vagrant,juiceinc/vagrant,Chhunlong/vagrant,cgvarela/vagrant,marxarelli/vagrant,aneeshusa/vagrant,pwnall/vagrant,wkolean/vagrant,juiceinc/vagrant,iNecas/vagrant,clinstid/vagrant,tknerr/vagrant,sax/vagrant,zsjohny/vagrant,TheBigBear/vagrant,sni/vagrant,obnoxxx/vagrant,ianmiell/vagrant,mwarren/vagrant,modulexcite/vagrant,clinstid/vagrant,marxarelli/vagrant,jhoblitt/vagrant,denisbr/vagrant,nickryand/vagrant,h4ck3rm1k3/vagrant,mwrock/vagrant,krig/vagrant,Chhunlong/vagrant,MiLk/vagrant,johntron/vagrant,sni/vagrant,carlosefr/vagrant,jtopper/vagrant,mwrock/vagrant,jean/vagrant,muhanadra/vagrant,aaam/vagrant,johntron/vagrant,patrys/vagrant,gajdaw/vagrant,evverx/vagrant,sni/vagrant,wkolean/vagrant,darkn3rd/vagrant,kalabiyau/vagrant,signed8bit/vagrant,miguel250/vagrant,kamazee/vagrant,tjanez/vagrant,tschortsch/vagrant,denisbr/vagrant,invernizzi-at-google/vagrant,senglin/vagrant,gbarberi/vagrant,ferventcoder/vagrant,jmanero/vagrant,ianmiell/vagrant,mpoeter/vagrant,ArloL/vagrant,patrys/vagrant,aneeshusa/vagrant,p0deje/vagrant,gbarberi/vagrant,Endika/vagrant,dustymabe/vagrant,dharmab/vagrant,apertoso/vagrant,TheBigBear/vagrant,vamegh/vagrant,otagi/vagrant,loren-osborn/vagrant,otagi/vagrant,tknerr/vagrant,dharmab/vagrant,mpoeter/vagrant,darkn3rd/vagrant,nickryand/vagrant,mitchellh/vagrant,teotihuacanada/vagrant,h4ck3rm1k3/vagrant,lukebakken/vagrant,cgvarela/vagrant,jberends/vagrant,benizi/vagrant,dhoer/vagrant,signed8bit/vagrant,sideci-sample/sideci-sample-vagrant,rivy/vagrant,jmanero/vagrant,Ninir/vagrant,legal90/vagrant,jfchevrette/vagrant,sax/vagrant,kalabiyau/vagrant,apertoso/vagrant,tbriggs-curse/vagrant,jhoblitt/vagrant,legal90/vagrant,Sgoettschkes/vagrant,doy/vagrant,legal90/vagrant,lukebakken/vagrant,jkburges/vagrant,philwrenn/vagrant,modulexcite/vagrant,fnewberg/vagrant,tschortsch/vagrant,wangfakang/vagrant,lukebakken/vagrant,jean/vagrant,janek-warchol/vagrant,obnoxxx/vagrant,bdwyertech/vagrant,wangfakang/vagrant,PatOShea/vagrant,invernizzi-at-google/vagrant,mkuzmin/vagrant,h4ck3rm1k3/vagrant,Chhed13/vagrant,tbarrongh/vagrant,gitebra/vagrant,kamazee/vagrant,apertoso/vagrant,sideci-sample/sideci-sample-vagrant,bdwyertech/vagrant,fnewberg/vagrant,lonniev/vagrant,TheBigBear/vagrant,krig/vagrant,tomfanning/vagrant,bheuvel/vagrant,Avira/vagrant,miguel250/vagrant,marxarelli/vagrant,tknerr/vagrant,evverx/vagrant,chrisvire/vagrant,bshurts/vagrant,tjanez/vagrant,theist/vagrant,tjanez/vagrant,iNecas/vagrant,Chhed13/vagrant,kalabiyau/vagrant,Chhed13/vagrant,gbarberi/vagrant,rivy/vagrant,Endika/vagrant,mitchellh/vagrant,tbarrongh/vagrant,PatrickLang/vagrant,mkuzmin/vagrant,gpkfr/vagrant,h4ck3rm1k3/vagrant,gitebra/vagrant,fnewberg/vagrant,kamigerami/vagrant,tbriggs-curse/vagrant,sferik/vagrant,jtopper/vagrant,janek-warchol/vagrant,loren-osborn/vagrant,wangfakang/vagrant,aaam/vagrant,jean/vagrant,ArloL/vagrant,BlakeMesdag/vagrant,ianmiell/vagrant,benh57/vagrant,ferventcoder/vagrant,bryson/vagrant,janek-warchol/vagrant,tknerr/vagrant,myrjola/vagrant,doy/vagrant,bryson/vagrant,tschortsch/vagrant,cgvarela/vagrant,channui/vagrant,Sgoettschkes/vagrant,kamigerami/vagrant,chrisroberts/vagrant,aneeshusa/vagrant,lukebakken/vagrant,theist/vagrant,signed8bit/vagrant,jkburges/vagrant,obnoxxx/vagrant,carlosefr/vagrant,bheuvel/vagrant