Switched testing to GitHub Actions

no issue

ghost/admin/.github/workflows/tests.yml

@@ -0,0 +1,28 @@
+name: Test Suite
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        browser: [ 'Firefox', 'Chrome' ]
+    name: ${{ matrix.browser }}
+    env:
+      MOZ_HEADLESS: 1
+      JOBS: 1
+      CI: true
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 10
+      - run: yarn
+      - run: yarn lint:js
+      - run: yarn test
+        env:
+          BROWSER: ${{ matrix.browser }}

ghost/admin/.travis.yml

@@ -1,23 +0,0 @@
-dist: xenial
-language: node_js
-node_js:
-- '10'
-- '12'
-cache: yarn
-env:
-  global:
-  - MOZ_HEADLESS=1
-  - JOBS=1
-# Don't run builds for renovate PRs
-if: NOT head_branch =~ ^renovate
-addons:
-  firefox: latest
-  chrome: stable
-install:
-- yarn
-script:
-- yarn run lint:js && yarn run test
-after_failure: |
-  if [ "${TRAVIS_EVENT_TYPE}" == "cron" ]; then
-    curl -X POST --data-urlencode "payload={\"attachments\": [{\"color\": \"danger\", \"fallback\": \"Build Failure: $TRAVIS_JOB_WEB_URL\", \"title\": \"Build Failure\", \"text\": \"$TRAVIS_JOB_WEB_URL\"}]}" $SLACK_URL
-  fi

ghost/admin/testem.js

@@ -1,18 +1,11 @@
 /* eslint-env node */
 /* eslint-disable camelcase */
 
-const isCronBuild = process.env.TRAVIS_EVENT_TYPE === 'cron';
-
-let launch_in_ci = ['Chrome'];
-
-// we only test Firefox in nightly builds on CI to keep push/PR build times lower
-if (isCronBuild) {
-    launch_in_ci.push('Firefox');
-}
+let launch_in_ci = [process.env.BROWSER || 'Chrome'];
 
 module.exports = {
     framework: 'mocha',
-    browser_disconnect_timeout: 30,
+    browser_disconnect_timeout: 60,
     test_page: 'tests/index.html?hidepassed',
     disable_watching: true,
     parallel: process.env.EMBER_EXAM_SPLIT_COUNT || 1,