Support for Backoff

[euonymos]

Summary

To handle automatically rate limit errors this PR allows clients to use exponential backoff with maximum delay threshold by optionally specifying these two options when creating an environment with mkMaestroEnv. This solves #39.

Type of Change

Please mark the relevant option(s) for your pull request:

• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update (adding or updating documentation related to the project)

Checklist

Please ensure that your pull request meets the following criteria:

• I have read the Contributing Guide
• My code follows the project's coding style and best practices
• My code is appropriately commented and includes relevant documentation
• I have added tests to cover my changes
• All new and existing tests pass
• I have updated the documentation, if necessary

Testing

• errors without backoff
• works with default backoff settings

TODO

• reformat code
• add MAESTRO_API_KEY in CI?

[sourabhxyz]

Thanks a lot @euonymos for this contribution! I would have a thorough look at it tomorrow. At the same time, we have this PR: #33 which is what is being used for in some of the other tools, like Atlas. If you would like, you can set target of this PR to maestro-org:drop-v0.

[euonymos]

Hey @sourabhxyz! I added a pair of tests, though they require an API key, so they will fail in CI. Not sure what's the best way to handle this. I also rebased on the branch you pointed out, thank you.

[sourabhxyz]

Thanks again @euonymos, I am merging this and would change few things slightly like changing the _ prefix in say _maeToken as I moved away from template haskell towards using generics for lenses.