docs(Makefile): upgrade version to 1.6.0

Author: LinkinStars

Makefile

@@ -1,6 +1,6 @@
 .PHONY: build clean ui
 
-VERSION=1.5.1
+VERSION=1.6.0
 BIN=answer
 DIR_SRC=./cmd/answer
 DOCKER_CMD=docker

README.md

@@ -23,7 +23,7 @@ To learn more about the project, visit [answer.apache.org](https://answer.apache
 ### Running with docker
 
 ```bash
-docker run -d -p 9080:80 -v answer-data:/data --name answer apache/answer:1.5.1
+docker run -d -p 9080:80 -v answer-data:/data --name answer apache/answer:1.6.0
 ```
 
 For more information, see [Installation](https://answer.apache.org/docs/installation).