Could not find init script on Debian 10.4 sysvinit

Issue

When including mattermost on a Debian 10.4 system using sysvinit (not systemd) I get the following error:

Error: Could not find init script for 'mattermost'
Error: /Stage[main]/Mattermost::Service/Service[mattermost]/ensure: change from 'stopped' to 'running' failed: Could not find init script for 'mattermost'
Notice: /Stage[main]/Mattermost/Anchor[mattermost::end]: Dependency Service[mattermost] has failures: true
Warning: /Stage[main]/Mattermost/Anchor[mattermost::end]: Skipping because of failed dependencies

Steps to reproduce

1. Install Debian 10 "buster" & bring the system up to date
2. Switch to sysvinit with the following commands:

   apt-get update
   apt-get --yes install sysvinit-core sysvinit-utils
   cp /usr/share/sysvinit/inittab /etc/inittab
   
   # Restart machine
   reboot
   
   apt-get remove --purge --auto-remove systemd

3. Include mattermost and execute a Puppet run