add mysql and prosgres test docker images fixgures

schema-registry-samples/docker-compose-postgres.yml

@@ -0,0 +1,14 @@
+version: '3'
+services:
+  postgres:
+    image: postgres:10
+    container_name: schema-registry-postgres
+    restart: always
+    environment:
+      POSTGRES_DB: registry
+      POSTGRES_USER: root
+      POSTGRES_PASSWORD: rootpw
+    expose:
+      - 5432
+    ports:
+      - 5432:5432