Add CI job to check MSRV. #87

# to view logs

	name: CI

	on: [push, pull_request]

	env:
	CARGO_TERM_COLOR: always
	MSRV: "1.56"

	jobs:
	test:
	name: "${{ matrix.os.name }} (${{ matrix.toolchain }})"
	continue-on-error: false
	runs-on: ${{ matrix.os.distro }}

	strategy:
	fail-fast: false
	matrix:
	os:
	- { name: Linux, distro: ubuntu-latest }
	- { name: Windows, distro: windows-latest }
	toolchain: [stable, beta, nightly]

	steps:
	- name: Checkout Sources
	uses: actions/checkout@v4

	- name: Install Rust
	uses: dtolnay/rust-toolchain@master
	with:
	toolchain: ${{ matrix.toolchain }}

	- name: Run Tests
	run: "cargo update && ./scripts/test.sh"
	shell: bash

	msrv:
	name: Check MSRV
	runs-on: ubuntu-latest

	steps:
	- name: Checkout Sources
	uses: actions/checkout@v4

	- name: Install Rust Nightly
	uses: dtolnay/rust-toolchain@nightly

	- name: Downgrade Dependencies to Minimal Versions
	run: cargo update -Z minimal-versions

	- name: Install MSRV (${{ env.MSRV }})
	uses: dtolnay/rust-toolchain@master
	with:
	toolchain: ${{ env.MSRV }}

	- name: Run Tests
	run: ./scripts/test.sh

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