[GEARPUMP-335] Set kafka tests log level to ERROR
[GEARPUMP-335] Set kafka tests log level to ERROR

Author: manuzhang <owenzhang1990@gmail.com>

Closes #205 from manuzhang/reduce_logs.

manuzhang/incubator-gearpump,manuzhang/incubator-gearpump,manuzhang/incubator-gearpump,manuzhang/incubator-gearpump,manuzhang/incubator-gearpump