[Merge] ~jibel/ubuntu-release-upgrader:fix_deb2snap_lp1856862 into ubuntu-release-upgrader:ubuntu/master

[Jean-Baptiste Lallement]

The proposal to merge ~jibel/ubuntu-release-upgrader:fix_deb2snap_lp1856862 into ubuntu-release-upgrader:ubuntu/master has been updated.

Commit message changed to:

Fixes for upgrade to focal:
- Release number 19.04 -> 20.04 on UI
- Do not install snaps during upgrade if corresponding deb package is not installed
- Fixed a crash when a snap is installed but not the deb.

For more details, see:
https://code.launchpad.net/~jibel/ubuntu-release-upgrader/+git/ubuntu-release-upgrader/+merge/376999
-- 
Your team Ubuntu Core Development Team is requested to review the proposed merge of ~jibel/ubuntu-release-upgrader:fix_deb2snap_lp1856862 into ubuntu-release-upgrader:ubuntu/master.