CBST-45: fix sdk import paths

The couchbase sdk has changed the way connection model is now imported
http://review.couchbase.org/#/c/42419/

this needs to be reflected in systest as well

Change-Id: I0ae724a9756c356f3cf796e59734649baac0b716
Reviewed-on: http://review.couchbase.org/43068
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Ketaki Gangal <ketakigangal@gmail.com>