Set up email notifications for jenkins.impala.io

We may want to set up email notifications for the new jenkins.impala.io instance. To do so we could use the Amazon Simple Email Service (SES). However this will require to have a validated email address to send the emails from.

We could ask the ASF for something like jenkins@impala.apache.org. If that does not work, we might also consider using an @cloudera.com address, since Cloudera currently provides and administers the infrastructure. As yet another alternative, we might try to find a way to receive emails for jenkins@impala.io and use that one.