Adding integration test

.github/workflows/integration.yml

@@ -0,0 +1,39 @@
+name: integration-test
+
+on:
+# Trigger the workflow on push or pull request,
+# but only for the main branch
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+jobs:
+  integration-test:
+    runs-on: ubuntu-latest
+    env: 
+      flinkVersion: "1.9.0"
+      POSTGRES_DB: test_db
+      POSTGRES_USER: root
+      POSTGRES_PASSWORD: root
+      POSTGRES_HOST_AUTH_METHOD: trust
+    services:
+      postgres:
+        image: postgres:12.2-alpine
+      elasticsearch:
+        env:
+          xpack.security.enabled: false
+          discovery.type: single-node
+        image: docker.elastic.co/elasticsearch/elasticsearch:6.2.1
+        options: --entrypoint bin/elasticsearch
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up JDK 1.8
+        uses: actions/setup-java@v1
+        with:
+          java-version: 1.8
+      - name: Grant execute permission for gradlew
+        run: chmod +x gradlew
+      - name: Run test
+        run: PG_HOST=postgres ES_HOST=elasticsearch ./gradlew integrationTest