MB-32514: Migrate testapp_hello to nlohmann::json
MB-32514: Migrate testapp_hello to nlohmann::json

Change-Id: Idc6fff4baa4abfed2a235085664b993dabd589b1
Reviewed-on: http://review.couchbase.org/104145
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Trond Norbye <60edd2ef23891a753f231b0c6f161dc634079a93@couchbase.com>

daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine