CBQE-2602: quota_percent is always initialized to None, instead of param
value passed.
Fixing the basetestcase to handle the case where quota_percent is used
to size the node ram size.

Change-Id: I8e9939c9fdfc6a246eff5e5babb1002381f80d52
Reviewed-on: http://review.couchbase.org/33851
Reviewed-by: Ketaki Gangal <ketakigangal@gmail.com>
Tested-by: Ketaki Gangal <ketakigangal@gmail.com>