Add a bit of cache to commandTest
Issue #2014519 by helmo, clemens.tolboom: Fixed SQLite test fails due to missing path while restoring database.
Issue #2027703 by jonhattan: Fixed Drush make --prepare-install doesn't retain chmod values.
Issue #934472 by c960657, greg.1.anderson | robertDouglass: Fixed memcache is not cleared on 'drush cc theme'.
Enable testing of php 5.4 on travis