Notify of execution status

[aureq]

At the moment, this no way to determine if an execution has been done correctly. It would be welcome to somehow notify a system to inform of success of failure for each attempted issuance.

[aureq]

The idea is to use DynamoDB to store information about certificates that are available for deployment. The table key will be the host name and clients will be allowed to regularly query the table to determine if a recent change has happened. Fields should be:

• domain as the primate key
• date to represent the latest modification
• s3_region where the s3 bucket containing the material is
• bucket the bucket name in which the material is stored
• base_path a path within the bucket from where to retrieve the material
• private_key (bool) to indicate if the private key was (re)generated during the operation

Notes:

• Certificate and chain certificate should always be deployed, however the private key needs to be deployed only if it has changed. It's the client responsibility to deal with this efficiently.
• I don't know if base_path is good, or if the full path within the bucket for each item (key, cert, chain) should be used instead.

[aureq]

DynamoDB should be updated as soon as the certificate has been issued. Special care should be considered in the eventuality the update is throttled.

[aureq]

Reopening the issue due to aureq#25. The code should also deal efficiently with aureq#28 to ensure DynamoDB performances are changes and reverted at the end of a long running cycle.