Update UI's engines in package.json to could use node v15. The change is
motivated for apple M1 chip. If you have an apple M1 chip you need to
use node v15 to avoid errors while building the UI.
Update the node versions our UI's can use. These versions are specified
on the engines key in the package.json of each UI (admin and desktop).
Our UI's can run from node v10 to v14, we can not run on v15 because
ember-cli does not support it yet.
Carlos Alcaide