return results instead of none when CODS soiling signal is small

[martin-springer]

• Code changes are covered by tests
• Code changes have been evaluated for compatibility/integration with TrendAnalysis
• [ ] New functions added to __init__.py
• [ ] API.rst is up to date, along with other sphinx docs pages
• Example notebooks are rerun and differences in results scrutinized
• Updated changelog

[mdeceglie]

I re-ran the offending notebook and scrutinized the output to be sure no substantial changes occurred in the outputs. That plot does appear to change size, but I don't think it is a concern.

[martin-springer]

I added the CODS small signal test

[martin-springer]

I did update all packages in my conda environment and saved the notebook. Somehow, there's still a discrepancy in one cell. I could try re-creating a new environment the exact way nbval does here. On the other hand, we get quite a lot of warning and deprecation messages. Might be time to start resolving them.

[mdeceglie]

I think we can look past the notebook failure this time. I opened #401 today because of the message we're seeing in the notebook.

[mdeceglie]

Let's get the change log updated, then I think we can move forward with this. The version will be 2.2.0-beta.2

[martin-springer]

Sounds good, I updated the changelog. Could you merge these changes into aggregated_filters_for_trial as well and create a tag for the next pvfleets run?

[mdeceglie]

Looks good. Thanks @martin-springer!