set up postgres CI route

uses env flag TEST_POSTGRES since the sqlite test also runs with env flag CI true

.github/workflows/postgres-ci.yml

@@ -0,0 +1,27 @@
+name: Docker Image CI
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v1
+      - name: Build the docker-compose stack
+        env:
+          PG_USER: ci_db_user
+          PG_PASS: ci_db_pass
+        run: docker-compose up -d
+      - name: Sleep
+        uses: jakejarvis/wait-action@master
+        with:
+          time: '10s'
+      - name: Check running containers
+        run: docker ps
+      - uses: actions/setup-node@v1
+      - run: npm install
+      - name: Run test suite
+        env:
+          TEST_POSTGRES: true
+        run: npm test