Custom Interpolation Engine

[Alan D. Snow]

Currently there are two interpolation engines supported in configobj. It would be nice to be able to create you own interpolation engine for custom use cases. One example would be to implement features such as the variables in the serverless project:

https://www.serverless.com/framework/docs/providers/aws/guide/variables/

For example: ${ssm:/path/to/variable}

One way to officially support this would be to create an abstract base class based on InterpolationEngine for other projects to inherit from and create their own. Then, add an interpolation_engine kwarg to pass in this class to use when doing interpolation.

Thoughts? Ideas?

[Rob Dennis]

This is an interesting idea that would require someone who wants to take this on project on after I muster up the maintenance release