This is what I get when I try to upgrade mate from 19.10 to 20.04:

```
mae@HP-Compaq-6715b-Ubuntu-MATE:~$ sudo bash
[sudo] password for mae: 
root@HP-Compaq-6715b-Ubuntu-MATE:/home/mae# do-release-upgrade 

Checking for a new Ubuntu release

No new release found.

root@HP-Compaq-6715b-Ubuntu-MATE:/home/mae# 

```