Add metrics calculation app

[dfulu]

Pull Request

Description

Add a new app for scoring the cloudcasting model in production. The new cloudcasting metrics app takes all of the cloudcasting it times from the day before and scores them against the satellite ground truths

Completes #16

• New prediction scoring is stored in cloudcasting_metrics

Also:

• Refactor tests
• Update docs
• Modify entrypoints
• Change env name for clarity
• The model inference has been moved to cloudcasting_inference

Checklist:

• My code follows OCF's coding style guidelines
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I have checked my code and corrected any misspellings

[devsjc]

Nice, thanks for packaging it all sensibly!