MB-17955: Temporarily disable defragmenter_test in ep_testsuite
MB-17955: Temporarily disable defragmenter_test in ep_testsuite

Test frequently fails. Disabling temporarily until it's updated to be
more stable (in following commits).

Change-Id: Ic5d8afb597bd60978790901fde76b0611b208d54
Reviewed-on: http://review.couchbase.org/61230
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Jim Walker <1cd02e31b43620d7c664e038ca42a060d61727b9@couchbase.com>

daverigby/kv_engine,couchbase/ep-engine,daverigby/ep-engine,hisundar/ep-engine,daverigby/ep-engine,teligent-ru/ep-engine,teligent-ru/ep-engine,owendCB/ep-engine,daverigby/ep-engine,teligent-ru/ep-engine,membase/ep-engine,hisundar/ep-engine,daverigby/kv_engine,membase/ep-engine,owendCB/ep-engine,couchbase/ep-engine,hisundar/ep-engine,daverigby/ep-engine,owendCB/ep-engine,hisundar/ep-engine,owendCB/ep-engine,membase/ep-engine,couchbase/ep-engine,daverigby/kv_engine,teligent-ru/ep-engine,daverigby/kv_engine,couchbase/ep-engine,membase/ep-engine