Fix CI and update Elixir and OTP versions #173

# to view logs

	name: CI

	on:
	pull_request:
	push:
	branches:
	- main

	jobs:
	test:
	runs-on: ubuntu-20.04
	env:
	MIX_ENV: test
	GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
	strategy:
	fail-fast: false
	matrix:
	include:
	# Hard to test the oldest-supported version because rabbit_common and friends
	# are a bit hard to get compatibility right for. However, we don't really need
	# to do that here.
	- elixir: "1.16"
	otp: "26.2"

	# Latest-supported Elixir/OTP versions.
	- elixir: "1.17.3"
	otp: "27.1"
	lint: lint
	coverage: coverage
	steps:
	- name: Clone the repository
	uses: actions/checkout@v4

	- name: Start Docker
	run: docker compose up --detach

	- name: Install Erlang/OTP and Elixir
	uses: erlef/setup-beam@v1
	with:
	otp-version: ${{ matrix.otp }}
	elixir-version: ${{ matrix.elixir }}

	- name: Cache Mix dependencies
	uses: actions/cache@v4
	with:
	path: \|
	deps
	_build
	key: \|
	${{ runner.os }}-mix-${{ matrix.elixir }}-${{ matrix.otp }}-${{ hashFiles('**/mix.lock') }}
	restore-keys: \|
	${{ runner.os }}-mix-${{ matrix.elixir }}-${{ matrix.otp }}-

	- name: Fetch Mix dependencies
	run: mix deps.get

	- name: Run the formatter
	run: mix format --check-formatted
	if: ${{ matrix.lint }}

	- name: Check for unused dependencies
	run: mix deps.unlock --check-unused
	if: ${{ matrix.lint }}

	- name: Compile code and check for warnings
	run: mix compile --warnings-as-errors
	if: ${{ matrix.lint }}

	- name: Run tests
	run: mix test
	if: ${{ !matrix.coverage }}

	- name: Run tests with coverage
	run: mix coveralls.github
	if: ${{ matrix.coverage }}

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