added exists method for gcstorage #450

	# This workflow will install Python dependencies, run tests and lint with a single version of Python
	# For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions

	name: Python application

	on:
	push:
	pull_request:
	workflow_dispatch:

	jobs:
	build:

	runs-on: ubuntu-latest
	strategy:
	matrix:
	python-version: ["3.9", "3.10", "3.11"]

	steps:
	- uses: actions/checkout@v3
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v4
	with:
	python-version: ${{ matrix.python-version }}
	- name: Install dependencies
	run: \|
	python -m pip install --upgrade pip
	pip install pipenv
	pipenv install --dev --deploy --system
	- name: Lint
	run: \|
	./lint.sh
	- name: Test with pytest
	run: \|
	pytest

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