Close refresh / refresh_table queries correctly in Python Beeswax client
Close refresh / refresh_table queries correctly in Python Beeswax client

This patch ensures that calls to ImpalaBeeswaxClient.refresh* are closed after completion,
to ensure the query doesn't hang around for ever.

Change-Id: I1ac126755678c30d274454615f2db26cc2df7322
Reviewed-on: http://gerrit.ent.cloudera.com:8080/734
Reviewed-by: Henry Robinson <3eca10f30041813f045165784e24b5a950a6cc7e@cloudera.com>
Tested-by: Henry Robinson <3eca10f30041813f045165784e24b5a950a6cc7e@cloudera.com>

michaelhkw/incubator-impala,michaelhkw/incubator-impala,michaelhkw/incubator-impala,cloudera/Impala,michaelhkw/incubator-impala,michaelhkw/incubator-impala,cloudera/Impala,cloudera/Impala,michaelhkw/incubator-impala,michaelhkw/incubator-impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala