chore: migrate to Github Actions

.github/workflows/main.yaml

@@ -0,0 +1,45 @@
+name: CI
+
+on: [push]
+
+jobs:
+  ci:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+
+    - name: Use Node.js 10
+      uses: actions/setup-node@v1
+      with:
+        node-version: 10
+
+    - name: Cache dependencies
+      uses: actions/cache@v1
+      with:
+        path: node_modules
+        key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
+        restore-keys: |
+          ${{ runner.OS }}-yarn-${{ env.cache-name }}-
+          ${{ runner.OS }}-yarn-
+          ${{ runner.OS }}-
+
+    - name: Install dependencies
+      run: |
+        yarn --frozen-lockfile
+
+    - name: Lint files
+      run: |
+        yarn lint
+
+    - name: Typecheck files
+      run: |
+        yarn typescript
+
+    - name: Run unit tests
+      run: |
+        yarn test --coverage
+
+    - name: Build packages
+      run: |
+        yarn lerna run prepare