Meta: run reference-implementation tests on GitHub Actions

This makes the .travis.yml like the other repos to make changes from
whatwg/spec-factory#14 smaller.

.github/workflows/test.yml

@@ -0,0 +1,23 @@
+name: test
+on:
+  pull_request:
+    branches:
+    - master
+  push:
+    branches:
+    - master
+jobs:
+  test:
+    runs-on: ubuntu-20.04
+    defaults:
+      run:
+        working-directory: reference-implementation
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        submodules: true
+    - uses: actions/setup-node@v1
+      with:
+        node-version: 14
+    - run: npm install
+    - run: npm test

.travis.yml

@@ -1,16 +1,10 @@
-language: node_js
-node_js: stable
+language: generic
 
 env:
   global:
     - ENCRYPTION_LABEL="4a24edc7e7d1"
 
-before_install:
-  - cd reference-implementation
-
 script:
-  - npm test
-  - cd ..
   - make deploy
 
 branches: