[tests][m]: Setup Integration Tests with Cypress (#26).

* [cypress][s]-setup-integration=with-cypress
* [fix][s]- fix typescript bug 'All files must be modules when the '--isolatedModules' flag is provided' by adding an 'export {}' to all test files
* Fixes of cypress tests
* Use yarn everywhere not npm

Co-authored-by: Abhishek Gahlot <me@abhishek.it>

.github/workflows/main.yml

@@ -0,0 +1,16 @@
+name: Cypress Integration Tests
+on: [push]
+jobs:
+  cypress-run:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v1
+
+      - name: Cypress run
+        uses: cypress-io/github-action@v1
+        with:
+          browser: chrome
+          build: yarn run build
+          start: yarn start
+          wait-on: 'http://localhost:3000'