chore: added basic build workflow

.github/workflows/main.yml

@@ -0,0 +1,32 @@
+name: Build
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Setup node
+        uses: actions/setup-node@v2
+        with:
+          node-version: "14.17.0"
+
+      - name: Setup SSH to install dependencies
+        uses: webfactory/[email protected]
+        with:
+          ssh-private-key: ${{ secrets.SSH_PRIVATE_KEY }}
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build contracts to get the ABIs
+        run: npm run build
+
+      # TODO
+      # - name: Run tests
+      #   run: npm test