Add healthcheck container

To make certain of runnning database containers.

docker-compose.yml

@@ -1,14 +1,33 @@
-version: '2'
+version: '2.3'
 services:
   postgresql:
     image: postgres:9.5.12
     environment:
       POSTGRES_PASSWORD: ""
     ports:
       - "5432:5432"
+    healthcheck:
+      test: pg_isready -U postgres
+      start_period: 10s
+      interval: 10s
+      timeout: 30s
+      retries: 3
   mysql:
     image: mysql:5.7
     environment:
       MYSQL_ALLOW_EMPTY_PASSWORD: "yes"
     ports:
       - "3306:3306"
+    healthcheck:
+      test: mysqladmin -h 127.0.0.1 -uroot ping
+      start_period: 15s
+      interval: 10s
+      timeout: 30s
+      retries: 3
+  healthcheck:
+    image: busybox
+    depends_on:
+      postgresql:
+        condition: service_healthy
+      mysql:
+        condition: service_healthy