Workbench module that drops specified rows.

First, get up and running:

1. python3 ./setup.py test # to test Python
2. npm install && npm test # to test JavaScript

To add a feature on the Python side:

1. Write a test in test_droprowsbyposition.py
2. Run python3 ./setup.py test to prove it breaks
3. Edit droprowsbyposition.py to make the test pass
4. Run python3 ./setup.py test to prove it works
5. Commit and submit a pull request

To add a feature on the JavaScript side:

1. Write a test in support.test.js
2. Run npm test to prove it breaks
3. Edit support.mjs to make the test pass
4. Run npm test to prove it works
5. Commit and submit a pull request

To develop continuously on Workbench:

1. Check out the columnchart repository in a sibling directory to your checked-out Workbench code.
2. Start Workbench with bin/dev start
3. In a separate tab in the Workbench directory, run pipenv run ./manage.py develop-module droprowsbyposition
4. Edit this code; the module will be reloaded in Workbench immediately. In the Workbench website, modify parameters to execute the reloaded code.

For full instructions, see [developing your own modules](https://github.com/CJWorkbench/cjworkbench/wiki/Creating-A-Module)