解决npm WARN deprecated browsersli

npm WARN deprecated browserslist@2.11.3: Browserslist 2 could fail on reading Browserslist >3

.0 config used in other tools.                                                             

npm WARN deprecated bfj-node4@5.3.1: Switch to the `bfj` package for fixes and new features!

npm WARN deprecated json3@3.3.2: Please use the native JSON object instead of JSON 3       

npm WARN deprecated flatten@1.0.2: I wrote this module a very long time ago; you should use s

omething else.                                                                             

npm WARN deprecated browserslist@1.7.7: Browserslist 2 could fail on reading Browserslist >3.

0 config used in other tools.                                                               

npm WARN deprecated circular-json@0.3.3: CircularJSON is in maintenance only, flatted is its

successor.                                                                                 

npm WARN deprecated socks@1.1.10: If using 2.x branch, please upgrade to at least 2.1.6 to av

oid a serious bug with socket data flow and an import issue introduced in 2.1.0          

解决方法：

npm i browserslist