Bitrise API: Allow updating secrets

Description of the feature request

We would like to see the ability to programmatically update values for our secrets in bitrise.

Use case / for what or how I would use it

We would like to be able to rotate our AWS access keys that are utilized in bitrise hourly. So whenever our rotation service rotates those keys, we would like it to also be able to update bitrise’s secrets with those new keys.

Thank you! I will submit this to our feature request database for evaluation.