Replace Travis CI with GitHub actions

Sorry Travis. Still ❤️ you.

Author: mischah

.github/workflows/main.yml

@@ -0,0 +1,15 @@
+name: CI
+on:
+  - push
+  - pull_request
+jobs:
+  lint:
+    name: Run awesome-lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v2
+        with:
+          node-version: '16'
+      - run: npm install awesome-lint
+      - run: npm test