bf: fix orphan objects test
bf: fix orphan objects test

Now that we are actually emulating IO behavior using process.nextTick()
this test has to check for data deletion on the next tick, because
orphan objects are deleted async w/o waiting for a callback.

scality/S3,scality/S3,lucisilv/Silviu_S3-Antidote,truststamp/S3,tomateos/S3,scality/S3,lucisilv/Silviu_S3-Antidote,tomateos/S3,tomateos/S3,truststamp/S3,lucisilv/Silviu_S3-Antidote,tomateos/S3,lucisilv/Silviu_S3-Antidote,truststamp/S3,truststamp/S3,scality/S3,scality/S3,tomateos/S3,lucisilv/Silviu_S3-Antidote,tomateos/S3,truststamp/S3,truststamp/S3,truststamp/S3,lucisilv/Silviu_S3-Antidote,tomateos/S3,scality/S3,scality/S3,scality/S3,lucisilv/Silviu_S3-Antidote,tomateos/S3,truststamp/S3,lucisilv/Silviu_S3-Antidote