The following error is thrown when running the tap-postgres extractor with Meltano.

Steps to reproduce:
- Create a meltano project
- Follow the custom extractor installation instructions here
2a. Establish a target loader as well
- Run the following command:
meltano --log-level=debug elt tap-postgres target-X
The issue is resolved by navigating to the .meltano/extractors/tap-postgres/ and activating the virtual environment venv there and then installing simplejson with pip install simplejson