Alright, we have the module! and I'm sure no one is going to believe this.
We reinstalled the BIMserver a dozen times and spoke with GS at length today and still had no v18 module until finally someone there was convinced that when setting the masteradmin account --- wait for it --- the password must not contain any special characters!
I tried to change the existing password but that didn't work. Uninstall everything and reinstall the BIMserver using a simple pw for masteradmin. Mine only had a + and that seemed to be too much. Just letters, upper and lowercase, and if you're still feeling adventurous throw in a number, just no fancy sh_t like underscores, periods or symbols. It appears you could change the pw afterwards, however it is important that during the installation you keep it simple.
I hope this works for you.