Infrastructure: Swap to GitHub Action for JS linting (pull #1501)

Allows lint errors to show as inline comments on PRs.

.github/workflows/lint-js.yml

@@ -0,0 +1,36 @@
+name: JavaScript Linting
+on:
+  push:
+    paths:
+      - "package*.json"
+      - ".eslint*"
+      - "**/*.js"
+      - ".github/workflows/lint-js.yml"
+      - "!common/**"
+
+  pull_request:
+    paths:
+      - "package*.json"
+      - ".eslint*"
+      - "**/*.js"
+      - ".github/workflows/lint-js.yml"
+      - "!common/**"
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Clone repository
+        uses: actions/checkout@v2
+
+      # setup-node task is used without a particular version in order to load
+      # the ESLint problem matchers
+      - name: Set up Node.js
+        uses: actions/setup-node@v1
+
+      - name: Install npm dependencies
+        run: npm ci
+
+      - name: ESLint
+        run: npm run lint:es

.travis.yml

@@ -15,9 +15,6 @@ jobs:
     - env: ALLOW_FAILURE=true
 
   include:
-    - stage: Lint
-      name: JS Linting
-      script: npm run lint:es
     - stage: Lint
       name: HTML Linting
       script: npm run vnu-jar