Move variable export earlier in concourse documentation
Move variable export earlier in concourse documentation

so that it's ready before the erb file, not a last-minute export
evandbrown/bosh-google-cpi-release,evandbrown/bosh-google-cpi-release,evandbrown/bosh-google-cpi-release,evandbrown/bosh-google-cpi-release,cloudfoundry-incubator/bosh-google-cpi-release,cloudfoundry-incubator/bosh-google-cpi-release,cloudfoundry-incubator/bosh-google-cpi-release,cloudfoundry-incubator/bosh-google-cpi-release