update java sdk reference
update java sdk reference

use Groupmemebershipcollection instead of a generic collection

Change-Id: I69bfa499ae6aae9aa75af461e42ccac6cb3deed0

shelsonjava/box-android-sdk-v2,SteadfastInnovation/box-android-sdk-v2,SteadfastInnovation/box-android-sdk-v2,shelsonjava/box-android-sdk-v2