refactor: big refactor for making things strict #23

	name: CI

	on:
	push:
	branches:
	- '**' # matches every branch

	jobs:
	build:
	runs-on: ${{ matrix.os }}
	strategy:
	matrix:
	os: [ubuntu-latest, macos-latest]
	name: Build
	steps:
	- name: Checkout project
	uses: actions/checkout@v2
	with:
	fetch-depth: 0
	- name: Set up elan
	run: curl https://raw.githubusercontent.com/leanprover/elan/master/elan-init.sh -sSf \| sh -s -- -y
	- name: Build project
	run: ~/.elan/bin/lake build
	- name: Build tests
	run: ~/.elan/bin/lake build Tests
	test_external:
	needs: build
	runs-on: ${{ matrix.os }}
	strategy:
	matrix:
	os: [ubuntu-latest, macos-latest]
	name: Test
	steps:
	- name: Checkout project
	uses: actions/checkout@v2
	with:
	fetch-depth: 0
	- name: Set up elan
	run: \|
	set -o pipefail
	curl -sSfL https://github.com/leanprover/elan/releases/download/v1.4.2/elan-x86_64-unknown-linux-gnu.tar.gz \| tar xz
	./elan-init -y --default-toolchain none
	echo "$HOME/.elan/bin" >> $GITHUB_PATH
	sudo apt-get update
	sudo apt-get install -y --no-install-recommends libuv1-dev clang
	sudo update-alternatives --set cc /usr/bin/clang
	- name: Run tests
	run: \|
	~/.elan/bin/lake exe tests

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