Add GH Actions CI.

Author: rwjblue

.github/workflows/ci.yml

@@ -0,0 +1,66 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - master
+      - 'v*' # older version branches
+    tags:
+      - '*'
+  pull_request: {}
+  schedule:
+  - cron:  '0 6 * * 0' # weekly, on sundays
+
+jobs:
+  lint:
+    name: Linting
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+    - uses: actions/setup-node@v1
+      with:
+        node-version: 12.x
+    - name: install yarn
+      run: npm install -g yarn
+    - name: install dependencies
+      run: yarn install
+    - name: linting
+      run: yarn lint
+
+  test:
+    name: Tests
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      matrix:
+        node: ['^8.12.0', '10', '12']
+        os: [ubuntu-latest, windows-latest, macOS-latest]
+
+    steps:
+    - uses: actions/checkout@v1
+    - uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node }}
+    - name: install yarn
+      run: npm install --global yarn
+    - name: install dependencies
+      run: yarn
+    - name: test
+      run: yarn test
+
+  floating-test:
+    name: Floating dependencies
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+    - uses: actions/setup-node@v1
+      with:
+        node-version: '12.x'
+    - name: install yarn
+      run: npm install -g yarn
+    - name: install dependencies
+      run: yarn install --no-lockfile
+    - name: test
+      run: yarn test

package.json

@@ -29,6 +29,7 @@
     "test": "tests"
   },
   "scripts": {
+    "lint": "eslint .",
     "lint:js": "eslint .",
     "release": "release-it",
     "test": "qunit tests/**/*-test.js"