chore: Add github actions as CI server

.github/workflows/ubuntu.yml

@@ -0,0 +1,23 @@
+name: ubuntu
+
+on: [push, pull_request]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: Setup Node
+      uses: actions/setup-node@v1
+      with:
+        node-version: '12'
+    - name: Install yarn
+      run: curl -o- -L https://yarnpkg.com/install.sh | bash
+    - name: Install dependencies
+      run: yarn install
+    - name: Run tests 
+      run: yarn test
+    - name: Coveralls
+      uses: coverallsapp/github-action@master
+      with:
+        github-token: ${{ secrets.GITHUB_TOKEN }}