CBQE-1902: refactor cbRecoverytests

there are common parts for all tests in the beginning and the end of the tests

Change-Id: I6516547cbd1afec182b79b14ba402ff10ae365a5
Reviewed-on: http://review.couchbase.org/33258
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>