CBQE-1069: print test_params at the end of failed tests

Change-Id: I5deb4868b0871791dcc406fcae445d26bb1cca35
Reviewed-on: http://review.couchbase.org/25125
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>