align GitHub actions to other repos (#19)

Author: dastrobu

.github/workflows/build.yaml

@@ -0,0 +1,35 @@
+name: ci
+on:
+  - push
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: norio-nomura/[email protected]
+  macos-test:
+    strategy:
+      matrix:
+        swift-version:
+          - "5.5"
+          - "5.4"
+          - "5.3"
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: fwal/setup-swift@v1
+        with:
+          swift-version: ${{ matrix.swift-version }}
+      - run: swift test
+  linux-test:
+    strategy:
+      matrix:
+        swift-version:
+          - "5.5"
+          - "5.0"
+    runs-on: ubuntu-latest
+    container: swift:${{ matrix.swift-version }}
+    steps:
+      - uses: actions/checkout@v2
+      - run: swift test

.github/workflows/ci.yaml

@@ -2,7 +2,7 @@
 
 [![Swift](https://img.shields.io/badge/Swift-5.5-blue?logo=swift&logoColor=white)](https://swift.org)
 ![Platform](https://img.shields.io/badge/platform-x86__64--apple|x86__64--linux-lightgrey.svg)
-[![Build Status](https://img.shields.io/endpoint.svg?url=https%3A%2F%2Factions-badge.atrox.dev%2Fdastrobu%2Fargtree%2Fbadge&style=flat)](https://actions-badge.atrox.dev/dastrobu/argtree/goto)
+![Build](https://github.com/dastrobu/argtree/actions/workflows/ci.yaml/badge.svg)
 
 Command line argument parser package in Swift.