Allow for specifying checks in mix config #53

	name: Lints

	on:
	pull_request:
	branches: [ master ]

	jobs:
	store-pr:
	name: Store PR number
	runs-on: ubuntu-latest
	steps:
	- name: Save PR number
	run: \|
	mkdir -p ./pr
	echo ${{ github.event.number }} > ./pr/NR
	- uses: actions/upload-artifact@v2
	with:
	name: pr
	path: pr/

	formatting:
	name: Check formatting (invalid/format)
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2
	- name: Set up Elixir
	uses: erlef/setup-beam@v1
	with:
	otp-version: '24.0'
	elixir-version: '1.12.1'
	rebar3-version: '3.15.2'
	- name: Restore dependencies cache
	uses: actions/cache@v2
	with:
	path: deps
	key: ${{ runner.os }}-mix-${{ hashFiles('**/mix.lock') }}
	restore-keys: ${{ runner.os }}-mix-
	- name: Fetch dependencies
	run: mix deps.get
	- name: Check formatting
	run: mix format --check-formatted

	credo:
	name: Check our credo (invalid/credo)
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2
	- name: Set up Elixir
	uses: erlef/setup-beam@v1
	with:
	otp-version: '24.0'
	elixir-version: '1.12.1'
	rebar3-version: '3.15.2'
	- name: Restore dependencies cache
	uses: actions/cache@v2
	with:
	path: deps
	key: ${{ runner.os }}-mix-${{ hashFiles('**/mix.lock') }}
	restore-keys: ${{ runner.os }}-mix-
	- name: Install dependencies
	run: mix do deps.get, deps.compile
	- name: Run Credo
	run: mix credo --all

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