Description of change

I want to set my Pendo integration key without exposing it in a plain text config.json file. Following other Singer connectors, I added a few lines to utils.py which use environment variable X_PENDO_INTEGRATION_KEY if it exists and if x_pendo_integration_key isn't in config.json. It'll still throw an error if neither exists.

This would resolve #109.

Manual QA steps

I actually can't get any tests to run with python -m pytest --verbose. Can someone more familiar with this project confirm that command runs without import errors?

Risks

• This change is untested, and so shouldn't be trusted.

Rollback steps

• revert this branch

Code style

I tried to keep things as plain and explicit as possible:

if "x_pendo_integration_key" not in config:
    env_key = os.getenv("X_PENDO_INTEGRATION_KEY")
    if env_key is not None:
        config["x_pendo_integration_key"] = env_key

But it may not the most succinct way to do it--or even the best way. Feel free to change this to a better way.