Add instruction in README for how to upgrade slither #4060

	---
	name: Lint Code Base

	defaults:
	run:
	# To load bashrc
	shell: bash -ieo pipefail {0}

	on:
	pull_request:
	branches: [master, dev]
	schedule:
	# run CI every day even if no PRs/merges occur
	- cron: '0 12 * * *'

	jobs:
	build:
	name: Lint Code Base
	runs-on: ubuntu-latest

	steps:
	- name: Checkout Code
	uses: actions/checkout@v2

	- name: Set up Python 3.6
	uses: actions/setup-python@v3
	with:
	python-version: 3.6

	- name: Install dependencies
	run: \|
	pip install .
	pip install deepdiff numpy

	mkdir -p .github/linters
	cp pyproject.toml .github/linters

	- name: Lint everything else
	uses: github/super-linter/slim@v4.9.2
	if: always()
	env:
	# run linter on everything to catch preexisting problems
	VALIDATE_ALL_CODEBASE: true
	DEFAULT_BRANCH: master
	GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
	# Always false
	VALIDATE_PYTHON: false
	VALIDATE_PYTHON_PYLINT: false
	VALIDATE_PYTHON_BLACK: false
	VALIDATE_PYTHON_ISORT: false
	# Always false
	VALIDATE_JSON: false
	VALIDATE_JAVASCRIPT_STANDARD: false
	VALIDATE_PYTHON_FLAKE8: false
	VALIDATE_DOCKERFILE: false
	VALIDATE_DOCKERFILE_HADOLINT: false
	VALIDATE_EDITORCONFIG: false
	VALIDATE_JSCPD: false
	VALIDATE_PYTHON_MYPY: false
	SHELLCHECK_OPTS: "-e SC1090"
	FILTER_REGEX_EXCLUDE: .tests/..(json\|zip\|sol)

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