Added formatting to workflow (#4)

* Added js-beatify as dependency
* Formatted src/index.js
* Added CI formatting step

Author: webdevred

.github/workflows/test.yaml

@@ -12,6 +12,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/[email protected]
+      - name: Check formatting with js-beautify
+        run: |
+          npx js-beautify -r -n "**/*.js"
+          npx js-beautify -r -n "package.json"
+          git diff --exit-code
       - run: npm install
       - run: npm run build
       - name: Run action with inclusive upper bound