Upgrade pyxform version to 2.0.3

[RuthShryock]

Checklist

1. If you've added code that should be tested, add tests
2. If you've changed APIs, update (or create!) the documentation
3. Ensure the tests pass
4. Make sure that your code lints and that you've followed our coding style
5. Write a title and, if necessary, a description of your work suitable for publishing in our release notes
6. Mention any related issues in this repository (as #ISSUE) and in other repositories (as kobotoolbox/other#ISSUE)
7. Open an issue in the docs if there are UI/UX changes

Notes

Update pyxform to version 2.0.3. This also modifies the format of the xls file that we send to the pyxform method create_survey_from_xls. Before the xls was a Django FieldFile object but we now covert it into a binary stream using io.BytesIO to create a file-like object in order to be compatible with the pyxform updates.

Side note: I attempted to update to version 2.1.0 but it is not compatible with our environment.

This update is deployed to kf.du.kbtdev.org for testing.

[notion-workspace]

Update pyxform in kpi and formpack