Ignore test files used by automake 1.13

Change-Id: I14317c742f9ea8118e6c3249b56f0e5359a7d36a
Reviewed-on: http://review.couchbase.org/27206
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>