Use GitHub actions for CI

Author: thibaudcolas

.github/workflows/ci.yml

@@ -0,0 +1,24 @@
+name: Continuous Integration
+on: [push]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [12.x]
+
+    steps:
+      - uses: actions/checkout@v1
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v1
+        with:
+          node-version: ${{ matrix.node-version }}
+      - name: install, build, test
+        run: |
+          npm ci --no-optional --no-audit --progress=false
+          npm run lint
+          npm run test
+          npm pack --loglevel notice 2>&1 >/dev/null | sed -e 's/^npm notice //' && rm *.tgz
+        env:
+          CI: true

.travis.yml

@@ -1,6 +1,6 @@
 # [stylelint-config-torchbox](https://www.npmjs.com/package/stylelint-config-torchbox) [<img src="https://raw.githubusercontent.com/torchbox/stylelint-config-torchbox/master/.github/stylelint-logo.svg?sanitize=true" alt="Stylelint" width="90" height="90" align="right">](https://stylelint.io)
 
-[![stylelint-config-torchbox on npm](https://img.shields.io/npm/v/stylelint-config-torchbox.svg)](https://www.npmjs.com/package/stylelint-config-torchbox) [![Build Status](https://travis-ci.com/torchbox/stylelint-config-torchbox.svg?branch=master)](https://travis-ci.com/torchbox/stylelint-config-torchbox)
+[![stylelint-config-torchbox on npm](https://img.shields.io/npm/v/stylelint-config-torchbox.svg)](https://www.npmjs.com/package/stylelint-config-torchbox) [![Build status](https://github.com/actions/torchbox/stylelint-config-torchbox/.github/workflows/ci.yml/badge.svg)](https://github.com/torchbox/stylelint-config-torchbox/actions)
 
 > Shareable stylelint config for CSS and SCSS, following Torchbox’s code style.