Fix Google Compute Builder Documentation
Fix Google Compute Builder Documentation

Added required configuration option ssh_username to basic config
example.

grubernaut/packer,tas50/packer,pieter-lazzaro/packer,mitchellh/packer,pieter-lazzaro/packer,rnaveiras/packer,youhong316/packer,youhong316/packer,ricardclau/packer,mkuzmin/packer,tb3088/packer,KohlsTechnology/packer,p1-nico/packer,ChrisLundquist/packer,tb3088/packer,mitchellh/packer,KohlsTechnology/packer,routelastresort/packer,mkuzmin/packer,ricardclau/packer,grubernaut/packer,grubernaut/packer,pecigonzalo/packer,timsutton/packer,ChrisLundquist/packer,dave2/packer,paulmey/packer,dave2/packer,grubernaut/packer,KohlsTechnology/packer,youhong316/packer,tb3088/packer,timsutton/packer,ricardclau/packer,routelastresort/packer,timsutton/packer,rnaveiras/packer,ChrisLundquist/packer,tas50/packer,grubernaut/packer,routelastresort/packer,ChrisLundquist/packer,paulmey/packer,mkuzmin/packer,mitchellh/packer,timsutton/packer,hashicorp/packer,ricardclau/packer,grubernaut/packer,pieter-lazzaro/packer,p1-nico/packer,tb3088/packer,dave2/packer,mitchellh/packer,bryson/packer,ricardclau/packer,ChrisLundquist/packer,dave2/packer,bryson/packer,hashicorp/packer,bryson/packer,rnaveiras/packer,tb3088/packer,tas50/packer,dave2/packer,tb3088/packer,pieter-lazzaro/packer,tas50/packer,p1-nico/packer,ricardclau/packer,bryson/packer,mkuzmin/packer,rnaveiras/packer,ChrisLundquist/packer,paulmey/packer,youhong316/packer,mitchellh/packer,youhong316/packer,pieter-lazzaro/packer,p1-nico/packer,pieter-lazzaro/packer,bryson/packer,hashicorp/packer,pecigonzalo/packer,hashicorp/packer,pecigonzalo/packer,dave2/packer,KohlsTechnology/packer,timsutton/packer,tas50/packer,paulmey/packer,p1-nico/packer,mkuzmin/packer,p1-nico/packer,routelastresort/packer,KohlsTechnology/packer,paulmey/packer,youhong316/packer,bryson/packer,rnaveiras/packer,KohlsTechnology/packer,paulmey/packer,routelastresort/packer,timsutton/packer,rnaveiras/packer,tas50/packer,mkuzmin/packer,pecigonzalo/packer