Allow upgrades only from supported versions

Introduces the `can_upgrade_from` field which is a list of supported
versions. We can control upgrade process now by this field, so user
won't start upgrade from the Fuel versions that we have not tested for
upgrade.

Change-Id: Id56a09845ade075fa4751c7eb164e065d5cad2ef
Closes-Bug: #1392756
Merge "Allow upgrades only from supported versions"