chore(*): use GitHub Actions for CI (#738)

.github/workflows/CI.yml

@@ -0,0 +1,19 @@
+name: CI
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - run: yarn install --immutable
+      - run: yarn prettier:check
+      - run: yarn build:all
+      - run: yarn lint:all
+      - run: yarn test:all

.travis.yml

@@ -1,8 +0,0 @@
-language: node_js
-node_js:
-  - 'stable'
-script:
-  - yarn prettier:check
-  - yarn build:all
-  - yarn lint:all
-  - yarn test:all