Update README.md

Added instructions to run mongodb

Author: alfredfrancis

README.md

@@ -26,8 +26,11 @@ docker-compose exec iky_backend python manage.py init
 docker build -t iky_backend:2.0.0 .
 docker build -t iky_gateway:2.0.0 frontend/.
 
+# start a mongodb server
+docker run --name mongodb -d mongo:3.6
+
 # start iky backend
-docker run --name=iky_backend -e="APPLICATION_ENV=Production" iky_backend:2.0.0
+docker run --name=iky_backend --link mongodb:mongodb -e="APPLICATION_ENV=Production" iky_backend:2.0.0
 
 # setup default intents
 docker exec -it iky_backend python manage.py init