Bug 17356: [QA Follow-up] Minor changes to skeleton.perl

Bug 17356: [QA Follow-up] Minor changes to skeleton.perl

Due to the way the snippet is run, there is no need to add a use for
C4::Installer or define $dbh (just like $DBVersion).
The suggested code is commented (column_exists is not defined).
Just as in updatedatabase, CheckVersion is called. The version number
does not need to contain 16.06; if we do so, we should update this
number each release. The XXX's work just fine.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>