Exclude test files in packaging

[wilwade]

Problem

Test files were included in the package, but should not be.

Solution

Update the include list under package.json -> files

Steps to Verify:

1. npm run clean && npm run build
2. npm run pack (on this commit)
3. npm run pack (on previous comment)
4. See that nothing has changed except we removed test files

[github-actions[bot]]

	Warnings
:warning:	You haven't updated the changelog!

Generated by :no_entry_sign: dangerJS against d74d717a59d0974c440cd0db582410bd0ecccf74