use short temp dirs.
use short temp dirs.

Closes #2792

arizvisa/packer,rnaveiras/packer,arizvisa/packer,pvandervelde/packer,c22/packer,paulmey/packer,grubernaut/packer,jimmythedog/packer,tas50/packer,pieter-lazzaro/packer,mafrosis/packer,pvandervelde/packer,grubernaut/packer,quantang/packer,c22/packer,tsmolka/packer,paulmey/packer,mitchellh/packer,rickard-von-essen/packer,atlassian/packer,p1-nico/packer,grubernaut/packer,sneal/packer,bryson/packer,p1-nico/packer,tsmolka/packer,markpeek/packer,pieter-lazzaro/packer,taliesins/packer,sean-/packer,timsutton/packer,c22/packer,youhong316/packer,mafrosis/packer,sneal/packer,sneal/packer,tsmolka/packer,jimmythedog/packer,sneal/packer,timsutton/packer,boumenot/packer,KohlsTechnology/packer,arizvisa/packer,boumenot/packer,quantang/packer,ricardclau/packer,bryson/packer,jen20/packer,jen20/packer,pecigonzalo/packer,markpeek/packer,paulmey/packer,mkuzmin/packer,tas50/packer,dave2/packer,mitchellh/packer,ChrisLundquist/packer,youhong316/packer,dave2/packer,routelastresort/packer,zhuzhih2017/packer,dayglojesus/packer,grubernaut/packer,jen20/packer,mkuzmin/packer,atlassian/packer,KohlsTechnology/packer,arizvisa/packer,mkuzmin/packer,jen20/packer,bryson/packer,boumenot/packer,jimmythedog/packer,tb3088/packer,smaato/packer,quantang/packer,boumenot/packer,timsutton/packer,hashicorp/packer,hashicorp/packer,bryson/packer,sean-/packer,dave2/packer,rnaveiras/packer,tb3088/packer,mitchellh/packer,grubernaut/packer,dayglojesus/packer,rickard-von-essen/packer,taliesins/packer,mafrosis/packer,tas50/packer,markpeek/packer,atlassian/packer,taliesins/packer,ricardclau/packer,pecigonzalo/packer,youhong316/packer,pecigonzalo/packer,taliesins/packer,ricardclau/packer,smaato/packer,mkuzmin/packer,atlassian/packer,dave2/packer,smaato/packer,sean-/packer,ChrisLundquist/packer,rickard-von-essen/packer,ChrisLundquist/packer,KohlsTechnology/packer,KohlsTechnology/packer,taliesins/packer,dayglojesus/packer,taliesins/packer,ChrisLundquist/packer,youhong316/packer,smaato/packer,hashicorp/packer,mitchellh/packer,zhuzhih2017/packer,tb3088/packer,c22/packer,c22/packer,mkuzmin/packer,mafrosis/packer,pvandervelde/packer,routelastresort/packer,jen20/packer,KohlsTechnology/packer,KohlsTechnology/packer,arizvisa/packer,jimmythedog/packer,arizvisa/packer,paulmey/packer,tas50/packer,markpeek/packer,pvandervelde/packer,ricardclau/packer,rnaveiras/packer,dave2/packer,p1-nico/packer,rnaveiras/packer,routelastresort/packer,p1-nico/packer,tas50/packer,boumenot/packer,smaato/packer,atlassian/packer,pieter-lazzaro/packer,dave2/packer,tas50/packer,zhuzhih2017/packer,youhong316/packer,tsmolka/packer,pieter-lazzaro/packer,quantang/packer,markpeek/packer,hashicorp/packer,youhong316/packer,bryson/packer,pvandervelde/packer,zhuzhih2017/packer,paulmey/packer,timsutton/packer,sean-/packer,sean-/packer,zhuzhih2017/packer,sneal/packer,tsmolka/packer,timsutton/packer,routelastresort/packer,grubernaut/packer,tb3088/packer,sean-/packer,pieter-lazzaro/packer,mitchellh/packer,quantang/packer,paulmey/packer,tb3088/packer,dayglojesus/packer,rickard-von-essen/packer,zhuzhih2017/packer,pvandervelde/packer,rnaveiras/packer,jimmythedog/packer,ChrisLundquist/packer,p1-nico/packer,smaato/packer,ricardclau/packer,mkuzmin/packer,tb3088/packer,routelastresort/packer,atlassian/packer,bryson/packer,dayglojesus/packer,rnaveiras/packer,rickard-von-essen/packer,markpeek/packer,tsmolka/packer,ChrisLundquist/packer,timsutton/packer,jen20/packer,mafrosis/packer,p1-nico/packer,c22/packer,ricardclau/packer,pecigonzalo/packer,pieter-lazzaro/packer