Add shadows.py and repair the typo in gates.py #695

	name: ci
	on: [push, pull_request]
	jobs:
	tests:
	runs-on: ${{ matrix.os }}
	name: test
	strategy:
	matrix:
	os: [ubuntu-20.04, macos-latest] # macos-latest disabled to save quota
	python-version: [3.8]
	fail-fast: false
	steps:
	- uses: actions/checkout@v2
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v4
	with:
	python-version: ${{ matrix.python-version }}
	cache: "pip"
	- name: install dependencies
	run: \|
	python -m pip install --upgrade pip
	pip install --no-cache-dir -r requirements/requirements.txt
	pip install --no-cache-dir -r requirements/requirements-extra.txt
	pip install --no-cache-dir -r requirements/requirements-dev.txt
	pip install --no-cache-dir -r requirements/requirements-types.txt
	- name: black linter
	run: \|
	black . --check
	- name: mypy checker
	run: \|
	mypy tensorcircuit
	- name: pylint checker
	run: \|
	pylint tensorcircuit tests
	- name: test scripts
	run: \|
	pytest --cov=tensorcircuit --cov-report=xml -svv --benchmark-skip
	- name: Upload coverage to Codecov
	if: matrix.os == 'ubuntu-20.04'
	uses: codecov/codecov-action@v2
	with:
	verbose: true
	token: ${{ secrets.CODECOV_TOKEN }}
	- name: run example demos
	run: \|
	cd examples
	python mcnoise_check.py
	python vqnhe_h6.py
	python mcnoise_boost.py
	python quantumng.py
	python universal_lr.py
	python parameter_shift.py
	python mpsvsexact.py
	- name: setup build
	run: \|
	python3 setup.py build

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