Added first set of texture file format tests #50

	name: PR Validation

	on:
	pull_request:
	paths:
	- '*/.usd*'

	jobs:
	run-usdchecker:
	name: Run usdchecker
	runs-on: ubuntu-22.04

	steps:
	- name: Check out repository
	uses: actions/checkout@v3
	with:
	fetch-depth: 0

	- name: Get changed files
	id: changed-files
	uses: tj-actions/changed-files@v37
	with:
	files: \|
	*/.usd*
	files_ignore_from_source_file: .github/usdchecker-skiplist.txt

	- name: Set up Python
	uses: actions/setup-python@v4
	with:
	python-version: '3.7'

	- name: Install usd-core PyPI package
	run: pip install usd-core --user

	- name: Test usdchecker
	run: python .github/usdchecker.py --help

	- name: Run usdchecker on changed USD files
	run: \|
	set +e
	exit_code=0
	for file in ${{ steps.changed-files.outputs.all_changed_files }}; do
	echo "Checking $file"
	if ! python .github/usdchecker.py $file; then
	exit_code=1;
	fi
	done
	exit $exit_code

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