安装步骤 https://github.com/medcl/elasticsearch-analysis-ik
以插件形式安装：
[elsearch@localhost elasticsearch-5.6.5]$ ./bin/elasticsearch-plugin install https://github.com/medcl/elasticsearch-analysis-ik/releases/download/v5.6.5/elasticsearch-analysis-ik-5.6.5.zip #替换成自己的版本 -> Downloading https://github.com/medcl/elasticsearch-analysis-ik/releases/download/v5.6.5/elasticsearch-analysis-ik-5.6.5.zip [=================================================] 100%