fix packages.sh (#359)
fix packages.sh (#359)

It was failing with this error:
```
Err:4 http://archive.ubuntu.com/ubuntu cosmic Release
  404  Not Found [IP: 91.189.88.142 80]
```

This is because Ubuntu 18.10 is EOL.
Updated to use 20.04 that is latest LTS: https://wiki.ubuntu.com/Releases

Also updated go version to 1.14
deniszh/go-carbon,deniszh/go-carbon,deniszh/go-carbon,lomik/go-carbon,lomik/go-carbon,lomik/go-carbon