Update Github Actions (#390)

- Add CodeCov
- Make consistent filename and scripts
- Remove legacy travis

Note: eventually we should decouple build and test but having everything
consistent is better than inconsistent to me.

.github/workflows/node.js.yml → .github/workflows/main.yml

@@ -1,14 +1,9 @@
-# This workflow will do a clean install of node dependencies, cache/restore them, build the source code and run tests across different versions of node
-# For more information see: https://help.github.com/actions/language-and-framework-guides/using-nodejs-with-github-actions
-
-name: Node.js CI
+name: build
 
 on:
-  # run on push but only for the master branch
   push:
     branches:
       - main
-  # run for every pull request
   pull_request: {}
 jobs:
   main:
@@ -33,5 +28,8 @@ jobs:
       - name: ▶️ Run flow-typed script
         run: npm run flow-typed
 
-      - name: ▶️ Run test script
-        run: npm run test
+      - name: ▶️ Run build and test script
+        run: npm run build
+
+      - name: ⬆️ Upload karma coverage report
+        uses: codecov/codecov-action@v2