chore(build): add an initial variation of GitHUb actions for build

.github/workflows/build.yml

@@ -0,0 +1,37 @@
+name: Build and test
+on: [push]
+# on:
+#   push:
+#     branches: [ master ]
+#   pull_request:
+#     branches: [ master ]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v2
+        with:
+          name: Set up Node.js
+          # Should be in sync with .nvmrc
+          node-version: "14"
+          cache: "yarn"
+      - name: Install dependencies
+        run: yarn install --frozen-lockfile
+      - name: Generate source files for demo site
+        run: yarn demo:file-gen
+      - name: Build the lib
+        run: yarn lib:build
+      - name: Run lint
+        run: yarn lint
+      - name: Check code styles
+        run: yarn prettier --check --ignore-unknown *
+      - name: Build the demo site
+        run: yarn demo:build
+      - name: Test the lib
+        run: yarn ng test ng-recaptcha --code-coverage
+      - name: Upload code coverage results to coveralls
+        run: yarn coveralls < coverage/ng-recaptcha/lcov.info
+      - name: Run e2e tests for demo site
+        run: yarn ng e2e demo