Client credentials expired for long running tasks

Problem/Motivation

For long running tasks sending emails, the task may take longer than the expiration time of the temporary credentials used by the AWS SES client created by the aws → module when using a role ARN for authentication.

In that case AWS will return an ExpiredTokenException and the emails will stop being sent.

Steps to reproduce

1. Install the `amazon_ses` module
2. Configure the profile to use a role ARN for authtentification
3. Create a script that instantiate the `amazon_ses.handler` service and then, for example, sleeps for more than 1 hour (default duration of the token) before sending an email
4. Sending the email will fail with a "The security token included in the request is expired" error entry in the logs.

Proposed resolution

Catch the exception (TokenException) and recreate the client and retry sending the email?

Remaining tasks

Implement patch.

User interface changes

None.

API changes

None.

Data model changes

None.