Add backend selector #104

	name: CI

	on: [push, pull_request]

	jobs:
	build_and_test:
	strategy:
	fail-fast: false
	matrix:
	toolchain:
	- x86_64-unknown-linux-gnu
	- x86_64-apple-darwin
	version:
	- stable
	- nightly
	include:
	- toolchain: x86_64-unknown-linux-gnu
	os: ubuntu-latest
	- toolchain: x86_64-apple-darwin
	os: macOS-latest

	name: ${{ matrix.version }} - ${{ matrix.toolchain }}
	runs-on: ${{ matrix.os }}

	steps:
	- uses: actions/checkout@master

	- name: Install ${{ matrix.version }}
	uses: actions-rs/toolchain@v1
	with:
	toolchain: ${{ matrix.version }}-${{ matrix.toolchain }}
	default: true

	- name: check nightly - linux + windows
	if: matrix.version == 'nightly' && matrix.os != 'macOS-latest'
	uses: actions-rs/cargo@v1
	with:
	command: check
	args: --all --benches --bins --tests

	- name: check stable
	if: matrix.version == 'stable'
	uses: actions-rs/cargo@v1
	with:
	command: check
	args: --all --bins --tests

	- name: tests nightly - linux + windows
	if: matrix.version == 'nightly' && matrix.os != 'macOS-latest'
	uses: actions-rs/cargo@v1
	with:
	command: test
	args: --all

	- name: tests stable
	if: matrix.version == 'stable'
	uses: actions-rs/cargo@v1
	with:
	command: test
	args: --all

	check_fmt_and_docs:
	name: Checking fmt and docs
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@master

	- name: Setup
	uses: actions-rs/toolchain@v1
	with:
	toolchain: stable
	default: true
	components: rustfmt

	- name: fmt
	run: cargo fmt --all -- --check

	- name: doc
	run: cargo doc

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