Update Maintenance Gist File

boxstarter_maint_gist.txt

##Update Maintenance Gist File
# To run, use this URL:
# http://boxstarter.org/package/url?C:\Support\boxstarter_maint_gist1.txt

###### Boxstarter options
# Allow reboots
$Boxstarter.RebootOk=$true

# Is this a machine with no login password?
# $boxstarter.NoPassword=$True

# Save my password securely and auto-login after a reboot
# No password on this machine, so commented out
$Boxstarter.AutoLogin=$true 

# Update all installed Choco packages
# cup all -y --ignore-checksum

# Check for pending reboot and reboot if necessary
if (Test-PendingReboot) { Invoke-Reboot }

# Get Windows Updates, Install and Reboot if needed
Install-WindowsUpdate -getUpdatesFromMS -acceptEula

# Rinse and repeat
if (Test-PendingReboot) { Invoke-Reboot }

You could also just append your Gist raw URL instead of a local file path assuming you have external internet access on the machine where you want to run it.