Bump to 0.6

Change-Id: I2cd5560a2a9d8cd9c86161af2a9dacdc992c7bb9
Reviewed-on: http://review.couchbase.org/27551
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>