[Merge] ~brian-murray/ubuntu-release-upgrader:python-dbg-fix into ubuntu-release-upgrader:ubuntu/master

[Dimitri John Ledkov]

replacements should be extended to replate:
python-doc with python2-doc
python-dbg with python2-dbg

however, the following ones should have no replacement, and simply removed:
python-dev
libpython-dev
libpython-stdlib
libpython-dbg

-- 
https://code.launchpad.net/~brian-murray/ubuntu-release-upgrader/+git/ubuntu-release-upgrader/+merge/388513
Your team Ubuntu Core Development Team is requested to review the proposed merge of ~brian-murray/ubuntu-release-upgrader:python-dbg-fix into ubuntu-release-upgrader:ubuntu/master.