message: Use SES_REGION env var to configure region for email messenger when using SES.
  Also add some debug logging
diff: @@ -15,8 +15,16 @@ module.exports = class EmailMessenger {
  throw new Error(`Could not find defaultFrom in message sink params`);
  }
  + let config = { apiVersion: '2010-12-01' };
  +
  + if (process.env.SES_REGION) {
  + config.region = process.env.SES_REGION;
  + }
  +
  + log.debug(`Configuring email messenger using SES with config ${JSON.stringify(config,null,2)}`);
  +
  this.transporter = nodemailer.createTransport({
  - SES: new aws.SES({ apiVersion: '2010-12-01' })
  + SES: new aws.SES(config)
  }, {
  from: params.defaultFrom
  });
  @@ -27,6 +35,9 @@ module.exports = class EmailMessenger {
  throw new Error(`Could not find ${prop} in message sink params`);
  }
  });
  +
  + log.debug(`Configuring email messenger using SMTP with host: ${params.smtpHost}, user: ${params.smtpUser}, defaultFrom: ${params.defaultFrom} (password not logged)`);
  +
  this.transporter = nodemailer.createTransport({
  host: params.smtpHost,
  auth: {
  