AttributeError: 'float' object has no attribute 'add_metric'

[Thales Mello]

You can't load the metrics/ page.

The reason for that is:

• you define a gauge,
• in the next line you override it with the execution time in seconds
• then you try to access the add_metric on a float

https://github.com/robinhood/airflow-prometheus-exporter/blob/master/airflow_prometheus_exporter/prometheus_exporter.py#L285