Update the allocate_for_instance method to icehouse version

Change-Id: I39476e48328e4d4a37cd15c086e6dbde01bbde0a
Signed-off-by: Rosario Di Somma <rosario.disomma@dreamhost.com>
Merge pull request #24 from rodis/stable/icehouse

Update the allocate_for_instance method to icehouse version