.pop, .push, .shift, .unshift and << changes aren't committed to disk

[fluffyx]

This snippet shows how .pop doesn't persist changes to disk. You can replace line 3 with .push, .shift, .unshift, or db['test'] << 4 and watch them fail as well.

db = Daybreak::DB.new 'test.db'
db['test'] = [1, 2, 3]
db.pop #== 3
db['test'] #== [1, 2]
db.close

db = Daybreak::DB.new 'test.db'
db['test'] #== [1, 2, 3]