added e2e tests (#298)

- added e2e tests for
  - banner
  - history
  - intro
  - language
  - link
- added e2e workflow
- added cypress badge to README

.github/workflows/build.yml

@@ -2,9 +2,9 @@ name: lint and build
 
 on:
   push:
-    branches: [master, dev]
+    branches: [master]
   pull_request:
-    branches: [master, dev]
+    branches: [master]
 
 jobs:
   build:

.github/workflows/e2e.yml

@@ -0,0 +1,34 @@
+name: e2e
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  end2end:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        browser: ['e2e:chrome', 'e2e:firefox']
+    name: ${{ matrix.browser }}
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+      - name: Cache node_modules
+        uses: actions/cache@v1.1.0
+        with:
+          path: node_modules
+          key: node_modules
+      - name: Cache ~/.cache
+        uses: actions/cache@v1.1.0
+        with:
+          path: ~/.cache
+          key: cache
+      - name: install cypress dependencies
+        run: sudo apt-get install libgtk2.0-0 libgtk-3-0 libnotify-dev libgconf-2-4 libnss3 libxss1 libasound2 libxtst6 xauth xvfb
+      - name: Install dependencies
+        run: yarn install
+      - name: Run e2e in chrome
+        run: yarn ${{ matrix.browser }}