Switch to using GitHub actions for CI

Also test more node versions

.github/workflows/build.yml

@@ -0,0 +1,23 @@
+name: build
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: [ 10.x, 12.x, 14.x ]
+    steps:
+      - uses: actions/checkout@v2
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v1
+        with:
+          node-version: ${{ matrix.node-version }}
+      - run: npm ci
+      - run: npm run build
+      - run: npm test

.travis.yml

@@ -1,4 +0,0 @@
-language: node_js
-node_js:
-  - 10
-script: npm run build && npm test