Bump `syn` dependency to 2.0 and msrv to 1.56.0 #22

	name: CI

	on:
	push:
	branches:
	- master
	pull_request:

	jobs:
	# == CHECK == #
	check:
	name: Check nightly beta stable and MSRV
	runs-on: ubuntu-latest
	strategy:
	matrix:
	rust-toolchains:
	- 1.56.0
	- stable
	- beta
	cargo-locked: ["--locked", ""]
	steps:
	- name: Install Rust toolchain
	uses: actions-rs/toolchain@v1
	with:
	profile: minimal
	toolchain: ${{ matrix.rust-toolchains }}
	override: true

	- name: Clone repo
	uses: actions/checkout@v2

	- name: Update `Cargo.lock`
	if: matrix.cargo-locked != '--locked'
	run: cargo update

	- name: Cargo check
	uses: actions-rs/cargo@v1
	with:
	command: check
	args: ${{ matrix.cargo-locked }}

	# == BUILD & TEST == #
	build-and-test:
	name: Build and test
	runs-on: ${{ matrix.os }}
	needs: [check]
	strategy:
	fail-fast: false
	matrix:
	os:
	- ubuntu-latest
	- macos-latest
	- windows-latest
	rust-toolchains:
	- 1.56.0
	- stable
	- nightly
	steps:
	- name: Install Rust toolchain
	uses: actions-rs/toolchain@v1
	with:
	profile: default
	override: true
	toolchain: ${{ matrix.rust-toolchains }}

	- name: Clone repo
	uses: actions/checkout@v2

	- name: Cargo test (nightly)
	if: matrix.rust-toolchains == 'nightly'
	uses: actions-rs/cargo@v1
	with:
	command: test
	args: --features nightly

	- name: Cargo test
	if: matrix.rust-toolchains != 'nightly'
	uses: actions-rs/cargo@v1
	with:
	command: test

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